Sure, poorer people are also very busy, but i think the GP poster is using "time poor" to refer to people for whom time is their most scarce resource.

When i was a kid, i couldn't afford to buy all of the toys and games i wanted to, but i had plenty of time with the toys and games i did have. Now as an adult i can afford to buy whatever i want (within reason), but life gets in the way of me enjoying those things. I think "time poor" is just the latter part of that transition.

Also, "rich enough to buy human labor" is a silly phrase as well. If you've ever stopped at a coffee shop instead of brewing coffee yourself, or if you've purchased bread instead of farming your own wheat, you've "bought human labor". Don't try to paint willful employment as some evil.

Agreed to be fair, the saying better pertains to time-poor people but I didn't want to misrepresent the original idiom.

Both rich and poor people can be time-poor. Depends a lot on priority and values. I value spending time with my family and I will often trade money for time to enable that.

Half my comment was on readability. "Time-poor" reads better than "time poor" when no quotation marks are used. When using quotations like you did, either approach is fine.