Everyone likes to feel superior.
When Glocks came out, those who didn't own/like Glocks felt superior because they had aesthetically pleasing handguns made of blued steel, shiny alloys and beautiful wood, not angular black metal and ugly plastic.
Then it turned out that the Glocks worked surprisingly well, they were surprisingly durable. They even gained a strong following among knowledgeable gun owners. LE took to them like a duck to water.
Now having a pretty handgun wasn't enough for many people--in order to maintain that feeling of superiority they felt that they needed to campaign against black metal and plastic. And that's exactly what happened. The company was exploitational, the design was dangerously flawed, the frame will melt in the car, the owners are all stupid--likened to a suicide cult, even the advertising motto was attacked. Sure, there's some basis in fact for most of the vilification--has to be if it's going to be more than momentarily successful. But it's not really about the facts.
And, of course, Glock owners are people too. They wanted to feel superior too. So for every overblown attack, there was an overblown testimonial.
Now, there's not really that much attention paid to the facts on either side. People on both sides repeat things that were repeated to them by someone else who heard them repeated, pictures are posted out of context, anecdotes are twisted, invented, misconstrued.
It's great--everyone gets to feel superior and there are no casualties but the truth.
Do Glocks have problems? Sure, they're designed and manufactured by humans--they can't be perfect no matter what the slogan says.
Are Glocks dangerous? Not according to Dean Speir, perhaps the most noted Glock critic of them all. He goes so far as to post on his website that he carries a Glock 21 from time to time and that if you follow the manufacturer's cautions that Glocks are great. If you don't, you get the chance of becoming an anecdote.