Same as sheep2001, I think of that kind of collecting as no different to collecting stamps, coins and what-not.
I think it's a shame when people collect them and don't play them, as there are plenty of people out there, including myself and I'm sure many others on this site, that would love to get them and actually play them, even if only to see what they're like before being retired to a shelf. But I don't think it's strange in any way.
Also, thanks sheep2001. Until I saw your image, I didn't realise Game Collector had a 'Statistics' bar graph like that.