Desktop power users were on the Acorn, Amiga, Atari and PC.
As NeXT "acquired" Apple, Linux users thought OS X was the UNIX experience they were looking for, and since they were never part of Apple culture, keep getting their expectations wrong.
They never set out to build the ultimate power user machine, their target was still general consumers. They just happened to have the right product at the right time when everything else just failed to compete.
Had desktop linux been in a better state, or had MS built WSL earlier, things might look a lot different today.
That market always bought the cheapest machine (or "best value", by specs/$) they could find (or, if they were really an "idiot", the machine that Best Buy had the highest commission on), which would be a PC.
In the beige days, Apple's bread was buttered in the publishing market, once they moved to OS X, they got the "professional nerds who wanted UNIX but not doing sysadmin at home".
I'd call the power user market that - the kind of idiocy that's more interested in the process than the results.
The actual target market was "people that have a life outside computers".