It isn't 100 SP minimum, it is 10x the minimum account balance. Currently that is 10x3 SP = 30 SP. Natural growth in SP counts, as does reductions in the minimum (applies retroactively to older accounts). I think most of these will end up being redeemable, though I don't know what percentage of users will actually do so.

The attitude of the social media userbase is very different from the crypto user base in terms of not being so focused on getting the SP money out. Looking at SP as influence and karma (especially when received free and/or earned rather than purchased as speculation) rather than being a coin at all is a perspective that is under-appreciated from the crypto side.

Also, as the the user base has grown, the ways to earn have grown as well. For example, most non-retarded comments are getting upvotes now, which is a big change from the previous status quo of typically 0 votes per comment. Maybe it is only a few cents in most cases ($1 not terribly uncommon) but it is better than nothing, especially since people may most many comments per day.