re: If sales continue to decline, it has no choice except to match Chromebook style
That's a different market. One doesn't just make machines, one has to tailor them for the type of market and the professional work using a desktop is quite different from using a Chromebook just to just socialize and watch video and not have technical problems. They'll want to keep a top end professional market even if it is to attract programs which might then move down market to everyday consumer use.