Not hating on open source, just let people use what fits their expectations and needs and stop deterring them with gatekeeping :P
UX = user experience
I am currently using Sync, and while I agree that the UX is better I can also understand why so many on the Fediverse are against similar apps. They are here because corporations have ruined every other good thing on the internet and non-FOSS is very much associated with big corporations. While I would prefer that Sync were FOSS I also see the reality of Western society and how untenable creating an app would be without some kind of ad revenue. A majority of people are notoriously stingy and donations can only get you so far.