Think of the negative reputation the Unity engine gained among gamers, even though a lot of excellent games and even performant games (DSP) have been made with it.
More competitors does also raise the bar required for novelty, so it is possible that standards are also rising in parallel.
Unity + Steam just makes this process a bit easier and more streamlined. I think the new thing is that as well as the dickwads who are trying to rip people off, there are well-intentioned newbie or indie developers releasing their unpolished attempts. These folks couldn't publish their work in the old days, because making CDs costs money, while now they can.