One should temper that sentiment.
Aftermarket parts are often not all they're cracked up to be.
I've seen some bad results, from high-grade bolts that were actually imported counterfeits (and caused a U-2 to disintegrate in midair) to Chinese fenders that would leave a mile-wide gap when installed.
When you go to NAPA/Weaver/Kragen/AutoZone, are you going to research the origin of said parts to guarantee they're made by the same contractors that made the original?
I disagree. I'm a mechanic by trade, and premium aftermarket parts are as good or better then the OEM parts they replace in most cases. Now you have to use a little sense. when you ask for the Alternator at NAPA, and they give you three choices: 1 for $130 and one year warranty, 1 for $180 and a "limited" lifetime warranty, and 1 for $200 and a full Lifetime warranty, the third one is the one you want. And it's as goo or better then the OEM one.*
If you buy the bottom of the line import stuff at Advance and compare it to OEm yes, it'll compare badley. But buy Premium, and that's what you get, and still at about 15-20% under what the dealer will charge for it. List. I'll not even start with what you can get it for with a shop account.
And sometimes I research manufacturers, but I'm not going to here. That's why I said "useally" in that sentence. But in reality, as we discuss in the other thread, many "domestic" are made overseas, and an OEM part is as likely to come from china or brazil as an aftermarket one.