The only thing I see that zergs agree on in the SC2 forum is that terran vs. zerg is terran-favored. However, no two people seem to come up with the same reason for it. I've seen
1. Tank overkill
2. Ling weakness
3. Maurauder stim/health
4. Hellions vs. hydralisks
5. Medivac healing rate
6. Mule ease vs. queen difficulty
7. Zerg early game weakness
8. Zerg midgame weakness
all individually blamed for imbalance. Obviously some of these overlap, but I don't see any form of consensus as to what about zerg is imbalanced.
ZvT may be imba, but it would be better for everyone to agree one why as opposed to immediately blaming the strategy you just lost to last and assuming that you lost because of OP terran vs. you just being bad.