Ah ok. No effort for the dev, but Sony gets subscription revenue to potentially turn people off from buying new games. I disagree with your assessment that the risk to the developer is minimal. Devs depend on customers having to pay before finding out that their games suck. While I'm a fan of being able to try first some developers are going to lose sales. But that's kind of ok with me.
If it's true that a study shows more demos/trials = less sales because gamers think the game is shit, that's fine by me. More demos and trials the better.
It's on devs to make a good game, as opposed to buyer beware tactics of the games industry. One of the few that doesn't allow refunds unless you call customer service and hope they refund your digital copy. Physical games youre shit out of luck.
As for devs crying gamers will refund a game after they beat it, too bad. It's not like a 2 hour trial is going to have anyone coming close to beating any game unless it's an indie game. And this $34 whole/$45 retail threshold excludes all those small scale games. So the only devs who have to worry are ones who make big budget games that are shit or short games at about $45 US.
Believe it or not, you can even refund a book to a bookstore. As long as it's not tattered, you can technically plow through a novel over a weekend and refund it as long as it's still in good condition.