The only reason to upload skins you've made 'should' be that you think others 'might' just want to try/enjoy what you've done to modify your own.
It shouldn't be about dl counts or ratings, etc....though they can be diverting/enlightening.
It shouldn't be about constant revision/updating as a chore.  There is no 'law' requiring updates....none at all.   If a skin/theme is outdated and people don't 'like' it - so be it....they simply won't use it.  If YOU don't use it either because it's out of date/disfunctional and are suitably inspired you might want to revise it for your own benefit...and others will benefit as a simple by-product of that.
I'm currently working on version 6 of 'Antares for Litestep'.....all within a month or two....not for anyone's benefit but my own interest in extending functionality.....a couple of months of mucking with one theme only.....but it's done for personal enjoyment.  If others get a kick out of it too....well and good....