the fact of the matter is, It is darn hard to run across a total piece of crap modern manufactured gun.
yeah you may end up with a lemon, but if you grab another of the same model, it will likely work.
what it comes down to for most people is usually these things. I might be wrong on the order
1) name recognition. Kimber 60k 1911's DW 4500. Yeah it is hard to beat that name recognition.
2) price point. If you have 700 bucks you only have 700 bucks. So you look for things in that price point. 1000 dollar HK's are out.
3) aesthetics Yeah yeah all guns go boom but some just look cooler to you. That differs person to person other wise we would not see those glorious tiger striped 50AE Desert Eagles.
4) comfort including grip and weight. I think more people are looking at what feels good as opposed to one that had 19 rounds like a noticed in the 90's.
5) Capacity. people want bullets man. the more, the safer they feel.
My two cents in a world of 20 dollar bills.