Edit: Btw, today it's easier to publish games then in 2005 - also without steam.
There are many unique and great indie games I would never have known without Steam (exclusives like Zeno Clash and non-exclusives like SPAZ). "Steam" as a distributer was a bold experiment in 2003 (it could easily have been the end for valve). In my opinion it had a positive effect on gaming as a whole. While there are undeniable downsides on how Steam works, they are far outweighed by the benefits Steam has brought to gaming. And if it is only the "proof of concept" of digital distribution.
Many Steam "phobics" (or hipsters, imo) don't raise valid points in their critizism but simple repeat the age old mantras like ( "I don't own my games", "Steam wants to control me", "Gabe is stealing my food"). Their reasons aren't important for game developers, at least not important enough to warrant any special treatment for those minorities.
And all this talk about "mainstream" being inferior. Please, Baldurs Gate was one of the biggest mainstream titles of its time, same as Duke Nukem or even "console classics" like SMB 3. Half of GOGs catalogue are mainstream titles. Even PS:T was conceived as a mainstream title. In 1999 RPGs were those "high production, mass appeal corner" that today is covered by shooters. People who criticize a game solely on budget or the amount of people who like it are hipsters and idiots. Yes, Modern Warfare isn't the next Anachronox, but it never tried to be. Duke Nukem forever, however (XD) was imo a playable tribute for the old duke 3d and therefore alone just awesome.