If you want a low end gaming rig AMD CPUs are the way to go ....
Spot on .... IBM had a massive strategy change after Lou Gerstner took over IBM following their gargantuan losses amounting to $24 Billion in the period 1991 to 1993. He kicked off, and steered, the industry change from mainframe to client server. In 1997, he went on the "offensive" to regain IBM market position and reputation by buying Tivoli, a Corporate level of Client-Server software. Part of that strategy was a massive change in IBM PC Sales and management. They used Tivoli to open doors with Corporates, the PC Sales teams followed with the PC Hardware deals for the Corporate networks, the latter queued in the Software guys - that being his ultimate goal, shifting IBM focus to software and Client server. It took 10 years, but he transformed IBM into what it is now.
The latter is the reason IBM PC chips are the way they are, they meet the Corporate needs, any gaming sales are a nice bonus - gaming related PC/CPU sales are a drop in the bucket for them, but still nice to have. IBM make their dosh on client-server and related corporate software and hardware.
AMD knew there was no way they could compete long term in that market head to head - so they went for the budget end of the market, very lucrative in its own way. However for that history reason, its insane to try and equate IBM V AMD hardware, they are made for different markets, gaming sales is a bonus for both of them, and they sure as hell don't see each other as direct competitors - different market places altogether.