[intopieces]

>So why does Microsoft have to do something other companies aren't doing either?

The bigger the market share, the bigger commitment to users. Microsoft doesn't "have" to ensure their older OSes work on newer chips. That sentiment is just another way of indicating that the userbase may take action (like choose to keep systems even longer, leading to MSFT having to support Win7 even further into legacy than they did for XP).

As well, consider the enterprise customers who are entrenched in Win7 but absolutely need new machines for expansion, but can't commit to replacing all machines. What was simply buying new machines now turns into supporting a new OS in addition.