If you've ever used a custom lab, or processed your own (B&W film), you quickly see the problem w/ using Costco/Walmart/Walgreen's etc to process your film. If they do a good enough job for you, great. You're fortunate. But I didn't invest tons of money and time testing equipment, and shooting the best gear that I can afford to own, just to have it screwed up by minimally trained employees w/ only a fuzzy idea of photography. Finger prints, dust, scratches, etc. I'm sure we've all been down this road before. That doesn't make me a purist. It makes me a professional. Which has nothing to do w/ money. It means I use professional equipment, spend a lot of time learning my craft, and expect professional results. Who wouldn't?
One seldom gets a second opportunity to retake a shot, so better to have everything in your favor from the get go. Trust me, I can foul things up myself w/o any help, so IF I get the shots right, I want the rest of it to go right as well.