I think a large factor was that many engineers had a PC on their desk as well for MS Office, email, various corporate apps made in VB (before the web), and so f

I think a large factor was that many engineers had a PC on their desk as well for MS Office, email, various corporate apps made in VB (before the web), and so forth. When x86 & NT became good enough for whatever engineering application they were working with, there was a large incentive to switch that one to NT and consolidate everything on one machine.