Yes.
Just bought 2 J tickets today.
It's not a matter of "saving" money to have more when I arrive. I want to enjoy my trip and sitting for 2hr or 12 doesn't matter.
People do pay for Business/ First. If they didn't , it wouldn't exist.
Although many North American airlines allow easy upgrades, most of the worlds airlines don't. People are paying to sit in J or F on Thai /SQ ect..