Well, I've said that I want carnifexes to be buffed. Twice already. Now it's three times

.
I just think that making them as terrifying as they used to be in 2nd doesn't reflect the status of a 100ish points unit in 9th. That's it. You might want a 100-120ish points unit that is worthy of that cost, I think it's perfectly reasonable to ask for a much more expensive unit if someone misses the 2nd version of the carnifex, remembering the impact it had on the game. Personally I'd prefer going with something close to the latter, a much better unit than what it is now but also considerably more expensive.
The idea of limiting units that can be spammed but arguably shouldn't be spammed (and that's entirely on
GW wether they are intended to be spammed or not, see planes) is not mine, it's something we've already witnessed. It might be silly for someone, to me it's silly to defend spam. Do you like tyranid monsters? Their codex has plenty of options to go with a lot of big dudes, there's no need to bring 6+ carnifexes for a proper nidzilla list. It's the same reason why I praised
GW patch about speedwaaagh lists: do you want to go full vehicles? Ork codex has a vast array of those, there aren't just dakkajets, scrapjets and squigbuggies to choose from.
I 100% want changes, and for tyranids in general not just about carnifexes, but good ones. I definitely wouldn't want an
OP 100ppm model that can be spammed in 6-9 as an autotake.