I think you may be underestimating the misstep IBM took with the PS/2 and the impact that tying their desktop systems to a proprietary MicroChannel Architecture had on their ability to compete with clone makers at a time when the PC market was rapidly expanding. They could not compete on price and could not compete on specs - and could not compete on customization in the PC market; the model 25 and 30 had limited expandability despite their ISA architecture. Throw in that they were pushing two obscure OS's and it's hard to lay the blame at Microsoft's door.
Furthermore, to characterize Microsoft as the dominate player in that partnership is simply rewriting history.
Furthermore, to characterize Microsoft as the dominate player in that partnership is simply rewriting history.