I totally agree! I actually went out of my way not to buy many Valentine cats (for more reasons than them not coming in toy & teacup sizes) so I'd not feel too committed and unable to enjoy these easter kitties as I'd feel overwhelmed by juggling two releases in my cattery at once, and I know Easter releases are always my favorite so I had to prioritize. My sim mate is the other way around and purchased tons of Valentine kitties and now feels so engaged in uncovering the mysteries of his Vday kitties that hearing about the Easter kitties made him really distraught.
I love this idea; I enjoy having so many releases (And each is so beautiful and unique!) but I agree that the spacing could be a bit better, I notice last year I did this too with taking a break between collections and not committing to a particular one because I didn't want to dread the next upcoming release as my cattery just can't handle hosting two releases at once.

I feel like this was the case with Halloween and Winter 2012 too as I had to plan out how many boxes I'd open and keep track of all starters and breeder kitties in my cattery to make it work and I witness plenty of others having to plan out in this way too.