At our company we are normally not allowed to order Mac laptops. An argument similar to the one in this post while pointing to my 2007 MBP that I was still using convinced my manager to shell out the extra $500 or so compared to the crappy HP laptop last year.
It's not that Macs last longer than PCs or are somehow more robust, most $1000+ machines will last longer than $500 machines.
My Lenovo W510 benchmarks the same or better than the T430s they're handing out now at my office. The only reason I have to upgrade is that I'd like a battery that last longer than the walk from 1 meeting to the next.
That was my point: they do last longer. Our preferred laptop was around $2,200 and the MBP came to around $2,800 (including Apple support) so they were both high end laptops. However, my colleagues who got the HPs two years ago already have had keyboard failures, characters on keys being rubbed off, etc. Not to mention the horrible cheap plastic feeling throughout that I feel after using a MBP for so long.
I think you're pigeon holing all PCs based on a bad experience with 1 brand. That's like saying all gasoline cars are poor quality and you should only buy electric cars based on a poor experience with GM.