The Linux opportunity, for example, wouldn't exist, if Microsoft and Intel hadn't created ubiquitous, low-cost, standard PCs.
I think I would quibble with the credit you give to MS for low cost PC's. The key thing driving costs down was the competition from clone makers building IBM compatibles. MS was included on these clones because it was on the IBM PC. During all of the 80's, MS had little that could compete with the Apple OS, and yet people bought IBM compatibles because they were lower cost. Why should MS get credit for that, since they did little to make this occur?
That continues to be the case. PC HW continues to both increase in functionality and decrease in price. The Windows OS and other products do increase in functionality, but their prices have not decreased over time like HW prices have.
I'll grant that MS was very shrewd in recognizing the strategic power of the OS and in leveraging this power (and revenue) into other areas, and that having one dominant SW provider reduces the issues of software compability (except between versions of MS products, of course.) However, without HW clones driving down HW prices, I don't think MS would have had anywhere near the success they had.