Nah, developers give PC players 60 for every game because they have I5class CPU's and its within the hardware capability without culling the game into oblivion with dumb AI and low enemy counts.
Devs choose money - what sells, not graphics or frame rate - 101. If devs can give 1800p and 60 FPS over a competitors 4K30, you bet they will. What do you think consumers would buy, 4K 30 or 1800p60 ?
Jaguar is not capable so there is no choice.
Frame rate on PC is dependant on hardware and the user's preference. There are endless settings both within the game, and using your graphic card control panel, as well as third party tools like Rivatuner.
I could lock the v-sync at 30hz and max all the settings, and crank up AA. Or I could aim to max framerate on a 144hz monitor, or lock it to 60hz and call it a day. PC gives users a choice, the developers don't decide what framerate someone on pc will play.
Even on PC people who game at 4k 60fps or 1440p 144hz are in a minority. The most used resolution is 1080p and lower end gpus that are a year old or more. Steam hardware surveys give an eye opening look at the reality of it's users.
I agree that developers (and more importantly Publishers) will aim to produce something that will maximise revenue, hence the sheer amount of micro transactions we see, and the push on online games.
I think you're overestimating the importance of framerate. People on forums like this are a minority, the average person who just walks into a shop buys Fifa and Call of Duty doesn't give a shit about the technology behind things. I bet if you were to stop 10 random people in a game shop and ask them if they heard of Digital Foundry the majority would have no idea what you were talking about.
It's the same principle with the likes of AVS and Avforums where members will get their tv's professionally calibrated, use receivers, examine the panel for defects such as backlight bleed, or uniformity issues on the lower IRE on an Oled.
The mainstream do not care about spending 2k on an oled, they walk into a brick and mortar store, buy a cheap Samsung as big as they can get and then burn their retina's in Dynamic mode watching sd sources on their 4k tv lol.