Lack of maintenance of singer-tap repositories: A lot of time when one wants to contribute a missing functionality or fix a bug there is literally no chance to merge the feature in the original tap. This leads to a bunch of forks being around (even some Meltano ones). When you want to use a new tap you first need to figure out which of those forks is most promising or where there is a chance to contribute

This is a fair point! We're trying to address this via the Meltano Hub and MeltanoLabs. We have plans to update the Hub to include more information to help folks make better decisions on which variant to use. The MeltanoLabs group has a few community-supported taps (and more are on the way) that way multiple people or organizations can contribute to them instead of just one or two. I agree it can be hard to figure out which taps are the most up to date versions or which issues are actually still relevant on repos sometimes.