Of course they don't owe anyone anything.

I still hope one or more of these experienced devs build lemmy apps. It is their experience and existing UI code base that I value. I'm glad that there are several new lemmy apps available, but the new devs will take years to achieve what the incumbents already have. I don't just mean code. The incumbents have already made plenty of mistakes and delt with complaints/suggestions from their userbase. They know what works for their users and can produce a polished lemmy with less time and effort than someone starting from scratch.