So as it has ever been, so it ever shall be
Verily I say unto you the wisdom of the ages: "Intel giveth. Microsoft taketh away."
From the dark days of yore as each increment of computer power, performance, efficiency came there was a need to blight the older tool with ware it could barely run, storage, memory and performance requirements it could barely meet, so as to sell unto the consumer a new box, a new license, new peripherals, and truly even all new apps. It is this plowing of the consumer population like a fallow field, turning over the harvested crop for new planting that drives the need for Microsoft's ware to do ever less well.
Their high priests became occult in the black art of obfuscating that most of the work applied by the wonderous new machine was applied to nothing at all, must contain more content never used, and ever more so in each generation until for them it became a Prime Doctrine never to be questioned. "Of course your computer no longer serves you as well as it did when it were new. Things wear out."
Though computers and software actually don't wear out, this heretical truth was driven from the land. Many generations of reaping they piled up the harvest of this plan. It was good to be King. Their installation grew ever more fat and slow.
That is the only answer to this question. Their art is bad because it is the art of bad.
Now there comes two new bands with new art, heretics who do not subscribe to such things. They each contend to be the new King. They must be warned: It is good to be king, but the retirement plan is very, very bad.