Some reasons I can think of for a map being good for 2 Hatch Muta are:
- short air distances
- open entrances for a third (like Blue Storm) so it's difficult to defend with 2 lurkers.
- being Soma
I am absolutely terrible at 2 Hatch Muta and I'd like to learn more about it, since going 3 Hatch Muta all the time makes me really predictable.