That's fine though. Less motivated people are less productive anyway, and we don't lose a lot, collectively, when they remain on the sidelines. They shouldn't be penalized for that though, at least not beyond not being less successful than they could be.
What we're really talking about is the threshold for how low we let people fall, and to me, that threshold should be a place to live, food to eat, and some spending money to contribute to the economy. Assuming most people agree (which is a huge assumption, granted), then it just becomes a question of the most efficient way to provide that. In my view, we currently do that by letting them work at McDonalds or WalMart, with mixed results, but a UBI might be a better way, particularly as low-skill labor becomes less and less necessary.
This taboo against "freeloading," like premarital sex, is mainly a moral judgment, not a practical one. Sure, they were both born of practical objections to the potential (even likely) consequences, but when those consequences can be easily mitigated or avoided, then the objections become less relevant. That's what progress looks like.