Either way, to me such a ratio doesn't exist. The only deciding factor is "Am I having fun within 2 hours" and if the answer is no to that, refund. If it yes, then purchase price becomes irrelevant, I own it to play it either through or until it ain't fun no more And replayability is a big factor for me, but not a deciding factor for purchase.
This was such a good move on Valve's part, which was long overdue, but probably helped a lot of companies. (Although I would question if it helped Arcen Games, only because their games are a little more complex and I could see people buying, trying to get into it and giving up within 2 hours and refunding it)
But considering I paid 19€ for Factorio and Played that 250 hours... or 20$ for KSP and played that for 250hours.. well yeah. Some games on the face seem vastly under-priced. But that's not how I think about purchases. I buy things I want nowadays, never again buying anything based on hearsay so the "value" element is really meh for me.
This has very much become my point of view over the years too, but I also have a very well paying job so I have the disposable income to drop the $60-$80 on a game that I may not get a lot out of.
Apparently based of my Steam Library at the moment I pay around $9.27CAD an hour... but that's probably off because I have 142 games I've never launched. (Purchases that were parts of bundles for other games I did want), and time accounted for by my father who plays his games in offline mode mostly. Currently out of my top 19 games (that's as much as I could fit into a screenshot lol) I have paid $1/hour for exactly one game, which is Ghost Recon: Wildlands, and even that isn't correct because it doesn't factor in the 70+ hours my father's put into the game in offline mode on my account. (the total should actually be around 135 hours according to my Ubisoft Profile)
edit: Yeah that number is way off because I also didn't buy TW:Warhammer for $25.
The point is that while yes it is important to get a good value for your money, at the same time it is important to have fun as well. So sure by all means use the $1/h ratio if you want, but remember that sometimes that won't line up, and you'll pay more for a game. It doesn't necessarily mean the game was bad, it simply means you didn't enjoy it. That's okay.
And before I finish Courtesy of SteamDB
https://steamdb.info my top 19 games, because apparently I'm all over the damn map on what I play.