Why does everyone use the MP5 in COD4?

I'm just curious. Out of Call of Duty 4's Submachine Guns weapon category, I believe (for me at least), the MP5 and Skorpion are the easiest to use. But why the MP5? it's not overpowered or anything; I went into a game with the skorpion and did very well. I do a little worse with the AK74U but I threw it on my Suppressed class to get challenges for it. The upward recoil kinda throws me off a bit. Same with the AK47. I still hafta experiemnt with the mini uzi and.. what's the other one.. is that it? Do the majority of players find it comfy? I just like how Call of Duty 4 introduced the perks and stuff :D Can play however you want. Like something? use it. Don't like it? Don't use it. lol