I really wasn't implying that I choose what I buy based on what films they've been in (though I'll admit, I do check out of curiosity, IMFDB makes that easy, and I know film far more than firearms), but if that's what someone does and they enjoy it, I don't think that's stupid at all.
My first firearms were purchased for purely aesthetic and filmic reasons. I had a script that called for a shotgun, a revolver, and a compact firearm that is only fired twice, so I ended up with a NEF Pardner, a Nagant, and a derringer. They looked interesting, they were cheap, and they were easy to find blanks for (aside from the Nagant, which had the benefit of the blanks being able to be seen on screen, as the shells for it are crimped like blanks). That's where my collection started.
I've never seen Giamatti and "sexy" in the same sentence, but I guess that's an exception. Desert Eagles are truly a "movie gun," they look great on screen and they're not really something a good guy on the run will just open a drawer and find. They're a meditated weapon, if that makes sense, something you're aware of and show. I had heard the armorers for the 2004 remake of Dawn of the Dead were requested to bring more "common" weapons to set when they brought them out, because they're not a survival situation, "I found this" or "just in case" kind of weapon. They're a weapon owner's weapon.