I used to think the same as you, but Glock has an extremely good reputation for taking incredible abuse and still work. Do an internet search for "torturetestGlock" and you'll see a torture test that should have killed any weapon, e.g. 8,000 rounds without cleaning, dropping it out of an airplane, etc... . The two hardest things I have to wrap my brain around is: 1) no owner operated safety switch and 2) it is really ugly.
I've used a pile of pistols over the years and I have to say that if I only had one pistol to carry, it would be a Glock. Also, with certain models, you can change out the caliber easily.
I can only comment that 8,000 rounds doesn’t mean a whole lot to me. What I’d be more interested in is how many of those 8,000 rounds were continuous, and what was the firing interval. Plastic (polymer), embedded rails and heat is the concern.