Sorry but you are having some selective memory. AMD actually was only a performance leader for a very brief period of time, that being the P4 days. That was also not because of anything great they did, but rather because the P4 ended up being a bad design because it did not scale as Intel thought it would. Outside of that they were competitive during the P3 days, but behind other than that.
They also had serious problems outside of any business practices from Intel. The three big ones that really screwed them today:
1) Their disastrous chipset situation. When the Athlons came out, their chipsets were garbage. The AMD made chipsets lacked any advanced features. The VIA chipsets were full featured, but poorly implemented. I bought an Athlon, excited at the performance upgrade I'd get from my P2 and drawn in by the price. I spent two weeks fighting and fighting to make it work, before finally finding out that GeForce graphics card were just incompatible with the boards because of VIA's out-of-spec AGP implementation. I sent it all back, got a P3 on an Intel chipset, and it all worked from the word go. Experiences like that really put many people and vendors off of AMD (combined with things like lacking a thermal halt on the chip so if a heatsink fell off the chip would bur out).
2) Their utter lack of innovation/resting on laurels. AMD took FOREVER to get out any kind of real new architecture, that being the Bulldozer, and it was poor when it happened. For too long they kept rehashing their same CPU architecture, while Intel kept moving theirs forward. This became particularly acute when the Sandy Bridge came out, which was a really good architecture improvement. Having nothing new and just trying to glom more cores on the server products was not a winning strategy long term.
3) Ignoring the software side of things. One of the things that makes Intel chips perform so well is their excellent compiler. It generates faster code than any other compiler, in every single test I've ever seen. That matters in the real world since people aren't going to waste time hand-optimizing assembly. Only recently did AMD get a compiler out (I haven't seen benchmarks on how good it is), for most of their life they just relied on other compilers and whined that the Intel compiler was mean to their chips. That has been a problem, particularly in research settings where people need high performance but are not primarily programmers and need something good at automatic code optimization.
AMD has done a lot to screw themselves over long periods and it has built up to a situation now where they are struggling in a big way. If you think Intel is all to blame you've your head in the sand.