SCO wasn't released until 89. Before that it was Xenix.

I remember my high school gf's father had a SCO Unix machine in his office. This was about 1991 I guess. At the time I was an Atari ST user, and just salivated at Unix machines (my luckier/older/wealthier Atari user friends had TT030s and got to play with Unix on them). Once she let me sneak into his office and play with it when he wasn't around, illicit unixing... was very exciting for me :-)

A few months later I got a 486 for graduation present and installed Linux 0.97 on it.

And if you didn't need the extra power you could get all the suffering of a Sun box for the cost of a common office PC.

I think that's why I've seen very few workstations using it, but it's pretty common as a shared industrial system. If you need a single user system you'd just use DOS, if you need a powerful workhorse you'd get a fancier system, possibly some newfangled RISC machine, but if you need a multitasking system and don't need much power for any individual task it's ideal.