Fair enough, I do it all the time and so do people in my friend group. There's a new game, it's on sale, I know I buy games on steam regularly, I buy the game, I try it, it doesn't work, it's not fun, something. I return it within the 2-hour window fairly regularly.
In fact, this steam two hour window has been part of game developer philosophy for a while, putting the good content first, so you don't get bored before the 2 hours expire. There's been a fair few reviews where people speculate this was just front-loaded so people don't return it
I think Steam NextFests have been a big part of the prevalence of demos. Before we had those, sure, a few games would have demos, but they wouldn't really gather much attention. NextFests are a good excuse for players to try a bunch of demos (think of the old demo discs that came with gaming magazines) and post about them on social media. This is a great way for smaller games to attract eyes, so now developers are more incentivized to actually produce demos, rather than just neat trailers and screenshots for marketing purposes.
I just don't like that everyone also does time-limited demos. Like you're only able to play the demo from this date to this date or something like that. Why not just keep the demo around for others who want a crack at it?
I remember the good old days of being super excited every time a new PCGamer magazine arrived in the mailbox and you'd get a fresh CD with it stuffed full of the hottest demos to try. Good times.
He has bills to pay like the rest of us, and considering he left traditional games media to start a crowdfunded project (NoClip), I doubt he would take a deal like this unless he needed to.