I don't see any issue with providing alternatives of either factory or community objects.
I think if you release something that is based off another users work, you should acknowledge this in the objects description e.g.
based on factory:osc/sine by Johannes Taelmann
this serves two purposes:
users may have put a lot of effort into some objects, so acknowledge it...
e.g. id might upset if someone took my wavetable object, added a simple bypass flag, and then passed it off as their own work - in my mind it shows a lack of respect
ii) access to original
the user will know where its come from, and so be able to see if perhaps the original is closer to their needs.
these 2 goals are at the heart of open source initiatives too, its not really about 'protection' its about fostering a community, and not upsetting others.
if course there is some leeway here, if you are inspired by another object, or make huge changes/re-implement it, then of course at some point it becomes your own work...
(e.g. just because ive seen how the factory objects do interpolation, doesn't really mean i have to credit this on every object which uses it, does it?)
one last point, of course the issue with creating derivatives is over time they might diverge, or even converge... ideally in open source, this is handled by collaboration, this could be done here, by working with the original author (if they are interested)
as an interesting side note, ive always wondered, at some point, if some object may be moved into the factory, as they are 'core' , and how we would manage that ... of course it would be 'with consent' but raises some questions