EPTNow, the immediate reaction many might have is "no, you need to give it more time!" That is understandable, however, I believe that the reasons why macro mechanics need to come back are based on facts that I have come to realize as a result of playing with the new patch as opposed to "not being used to new timings yet."
Worker Harass and Snowballing
All three of the macro mechanics, to some extent, help compensate for damage sustained due to worker harassment. MULEs, quite obviously, could make up for lost SCVs. Protoss could spend chrono on workers instead of upgrades or army to replenish worker count. Zerg could just pop out 50 more workers at once. You get the idea. With adepts, tank drops, overlord drops, and all of the goodies we still know and love from HotS, there are many ways to kill workers. Without these "macro mechanics" to compensate for dead workers, losing workers is now FAR more significant. In fact, losing too many workers now often times means losing the game as your losses snowball out of control.
Why are ways to compensate for worker losses good? Simply, I believe, because it makes for more exciting games. Games that are close or in which a player comes back from a deficit are more exciting to play and watch. Removing the macro mechanics makes coming back from losing workers more difficult. Losing a game because you weren't paying attention to your mineral line for a second or two isn't fun (at least for me).
Terran Economy is Broken
Over the past 5+ years since the WoL beta was out, Terran players have come to expect what we can afford per base count. For Protoss and Zerg players, this remains the same. Zerg players can afford just as much off of 2 saturated bases as they could before. Protoss players can also afford just as much off of 2 saturated bases as they could before with the caveat that they might need more production facilities because production takes more time. Terran players can suddenly afford a lot less per base. The 3 rax with addons + a reactor starport off of 2 base has been a staple of bio play since WoL. However, if you try this in the new LotV patch, you will barely be able to afford producing from all these buildings, not to mention starting upgrades and getting a third base. This is why Terran players in LotV have started going for fast 3 CC builds often after CC first.
At first, I thought that this is simply a matter of getting used to the new amount of income, as I'm sure many people still probably do. However, the more I played, the more I came to realize that all Terran unit costs are based on an economy in which Terran has MULEs. That's what the game has been balanced around for the past 5 years.
Another miner detail when it comes to the Terran economy is that SCVs are not mining when they're building units, which you usually do pretty often. This means that compared to Zerg and Protoss, the Terran economy starts off a good bit slower. MULEs used to compensate for this. Now, however, Terran seems perpetually behind, and "free money" supply drops are too little too late.
Terran Late Game
This has been addressed before, but it's worth repeating, I think. With MULEs, Terrans could sacrifice SCVs in the late game and replace the supply with army units. This balanced out the fact that Protoss and Zerg deal better with losing a maxed army - zerg players can remake dozens of units at once, while Protoss can warp in units very quickly. Terran players, on the other hand, have to wait for units to be produced and come out individually out of production facilities. If there are enemy units in the Terran production, the Terran won't be able to remake an army because the units will be picked of individually. Without MULEs, Terrans now no longer have the advantage of a larger army in the late game to compensate for the inferior remaxing capabilities.
Zerg is Less Reactive
I'm going to ignore the concept of auto-inject for now. Let's talk about having less larva in general. One of the cornerstones of zerg play (and one of the ways in which better zergs could differentiate themselves) is greedy droning and building units at the last second. With a smaller amount of larva (at least in the early-mid game), zergs need to make units before they see an army move out. Otherwise, the zerg didn't have enough larva to produce an army large enough to repel whatever attack is coming at them. This results in zergs building up a force gradually instead of the (IMO more zerg-y) building up an army quickly. This eliminates, to some extent, options that zergs used to have to punish greedy builds early on.
For the most part, this change isn't quite game breaking, but rather IMO, it makes the game less interesting.
Chrono Boost
Protoss upgrade times were increased a good bit back because of chrono boost. Now, Protoss units are simply slower to upgrade. Fortunately for Protoss, Adepts exist, so this isn't currently too much of an issue Kappa. While as a Terran player, I certainly appreciate not having to deal with an Oracle that is chrono boosted out or 1 base blink that is chrono boosted out, there are times that Protoss does rely on chrono boosting out units for defensive purposes. The issue with changing timings for Protoss units and upgrades is that decreasing the build time or research time could easily be too good in one area of the game. For instance, decreasing Phoenix build time could easily be abusable, and yet sometimes chrono boosting out phoenixes to deal with, say, mutas or liberators is sometimes necessary. Chrono boost gives a really nice balance of faster production for the units you need but not for others, which gives Protoss more flexibility.
Conclusion
Granted, I do believe that a good portion of these issues could be fixed by adjusting the cost, damage, and other stats of almost every unit and upgrade in the game, however, I do not believe that the game is "better off" without the macro mechanics, which makes attempting to rebalance the game around the lack thereof somewhat pointless.
This is the main point that is up to debate, I think. Should we cater to more casual players, for instance, by keeping auto-injects or should we reward mechanically skilled players that can keep up? Which is more important?
For the most part, I believe that the macro mechanics make SC2 a more interesting, dynamic, and fun game. The choice of chrono boosting probes vs upgrades vs units is very interesting and fun. The choice and cost of scanning as opposed to dropping a mule is equally interesting. However, if we do want to remove the macro mechanics, the game is going to require significant changes across the board before it is a good place.
