Not sure what your are trying to say or if you even use an iOS product. You can easily play music/movies not purchased through iTunes and there is other software out there that allows people to manage music/movies if they don't want to use iTunes. So no, it's really not the same thing at all.
Apple certainly could have made it easier to put any old video you want into iTunes, I think they made a strategic decision to coax people into purchasing video through iTunes by making it hard to just drop AVIs into it. If they had tried this with iTunes - come out with the music store before the player and limited you to only listening to music you bought through the store, they'd have been dead in the water. I'm sure they're more than happy with the sales of videos in iTunes but they certainly left a pretty wide hole where iTunes could have been the default video player for everything instead of just their own stuff.
The version of the iTunes Music Store where people can put whatever media they want up for sale sounds, to me, as a consumer, less valuable than the single place I can go now to get almost any album on any label I normally listen to, or get the most recent episode of Parks & Rec. I'm sure there's great stuff on sale at flea markets too, but I don't want to shop there. Sorry.
> The version of the iTunes Music Store where people can put whatever media they want up for sale sounds
The op doesn't mean that iTunes would be used for selling media. Rather it'd be your personal media player for everything like AVI/Mpeg/etc. like VLC is.
I don't know how well iTunes can do this as is, but that's what he's arguing for.