It's an entirely different codebase. Lemmy is written in Rust, PieFed in Python. If you're a Python developer you're not going to randomly learn Rust to contribute to the huge existing codebase that is Lemmy, and even if you did you might have a different stance than the Lemmy developers calling for a fork.
Furthermore, it's not a zero sum game. The projects share content, and both benefit from the success of the other.
I'm fine with it whilst there are maintainers with the whole "transgenderism is bourgeoise decadence" stance going on. I've happily worked with MLs and MLMs, I'm not a fan of bigots who work backwards to fit their ideology to their prejudices.
While that is a reasonable motivation, I'd be more worried about potential fracturing of the marketshare, preventing the critical mass to be reached for smaller ones, while keeping the bigger ones from reaching full potential.
The flame dying out for kbin comes to mind. Mastodon probably saw this and decided they need to up their game.
If we're talking about feature, wouldn't it be better to improve on the existing?
I'm definitely not an expert on this, but I find it concerning the massive closed players keep getting all the pies while preying on the players on the verse, waiting to see some weakness to prey on.
I mean, it’s being federated to Lemmy and most of us just see the Lemmy software as the open Reddit alternative. I’m still not quite sure what Piefed is like, I’ve pretty much never had to look past Lemmy and Mastodon.