It was Ken Olsen who said "There is no reason for an individual to have a computer in his home". Gates denies ever saying the quote attributed to him.
Neither quotes (whether correctly attributed) at the time were right. Anyone who could see the potential for computing would push on which is how we got here at all. Computers in the work place means familiarity hence business opportunities to sell into the home so no short sightedness there.
Devs used to compete to squeeze the most "stuff" into the smallest size (code parties / demo coding) but we've gained and used more resources because Devs pushed boundaries and demanded more - it didn't happen by accident.
You can happily run 10g on certified Cat6 (not cheap) and appropriate (read mega expensive) hardware. Pretty sure it's still more cost effective to use fibre optic if you really do need those speeds.
No demand? More and more people are using streaming services that offer 4k in a variety of heavily compressed and/or compromised ways. You think this won't increase? You think that having real 4K isn't desirable? Or 8K or 16K?
How about a household of devices all doing "stuff" over the internet, it isn't just about speed, it's about bandwidth. It's pretty easy to overwhelm a household connection (and no I don't mean the wifi router
).
I look forward to having fibre to the premises.