> That said, high price killed off most of the legacy Unix vendors/products.
High price and the differentiation. In the 90s I was working in publishing and publishing-adjacent companies that were throwing out their Unix environments as quick as they could after NT 4 was released. They were all sick of dealing with the crap of having multiple, subtly incompatible *ix environments to deal with: one company I worked for had Irix, AIX, SunOS, Solaris, and both flavours of Digital's Unix products, because various vendors had done deals with the different vendors to ship their products on those variants. Each came with different shells, different userlands, and all required slightly different tweaking and tuning to maintain operationally.
Contrast that with the NT 4 world, where that same business was quite happy to buy extremely expensive Alpha/NT systems so that the same skills, tool, and so on that worked everywhere.
High price and the differentiation. In the 90s I was working in publishing and publishing-adjacent companies that were throwing out their Unix environments as quick as they could after NT 4 was released. They were all sick of dealing with the crap of having multiple, subtly incompatible *ix environments to deal with: one company I worked for had Irix, AIX, SunOS, Solaris, and both flavours of Digital's Unix products, because various vendors had done deals with the different vendors to ship their products on those variants. Each came with different shells, different userlands, and all required slightly different tweaking and tuning to maintain operationally.
Contrast that with the NT 4 world, where that same business was quite happy to buy extremely expensive Alpha/NT systems so that the same skills, tool, and so on that worked everywhere.