Some of the issues for armorers is ease of use and reliability. Glocks and Berettas in particular are easy to convert to blank fire, and they do so very reliably. They can take a beating and keep firing.
Try getting a Lorcin to fire real bullets reliably. It won't. I owned one. They make a very nice paperweight. Converting it to blank fire may be putting an actors life in jeopardy!
They didn't have Glocks in the 70's, or you'd of seen them in every film back then too.
Politics is also a factor today. They don't make the guns "characters" because they don't want that kind of attention on the film. They don't want the guns to be the focus in any way shape or form. More than likely the producers and the director are anti-gun anyway.
And many movies have characters with illegally obtained guns using the guns to perform illegal and immoral acts. That matters. You also see characters using the guns in a blatantly unsafe fashion. Lethal Weapon 4 for instance. They point loaded guns at each other jokingly every 10 seconds. This has become our "gun culture".
I think the last time I saw a prominent Hi-power in a movie was The Matrix. Though didn't they have some in the newest Mummy flick?
TV shows these days use a lot of non-guns. NCIS: LA and Sons of Anarchy use them all the time. And TV is all about cop shows, and cops use Glocks, and Sigs. The occasional 1911 (Numb3rs) or out of place Walther (Walker Texas Ranger) always make me wonder how they got there in the first place.
