Toby Fox is a modder who happened to make an original game, but without shaking off his modder mentality. Everything he does is extremely derivative of things he thinks are cool.
This is quite common in all creative fields: there is a truly creative minority that inspires everyone, and there are the competent ones who know how to make entertaining things, but who don't have that same creativity, so they draw heavily on that creative minority for inspiration.
Personally, I think the first category (which Toby Fox is not included in) is the really interesting one. I prefer something a little crude, but which is the result of true originality, rather than the more polished things that come later, based on the creativity of the true pioneers.