Everyone needs to remember that these DLC packages are OFFICIAL R¤ RELEASES. These aren't community mods. They're intended for GTA V and when you download/install them, they become a part of GTA V. In a way, they can be seen as updates. Updates are meant to fix issues whether that issue is a bug or the lack of content in a certain area. We allow a IV runner to use whichever version of the game they want and I'm aware this isn't quite the same, but it's still considered DLC. It's content, you're downloading it and it updates the game.

Update: an act of bringing something or someone up to date, or an updated version of something.

Have a problem with exclusiveness? : VICE CITY PEOPLE!!! Have a problem with paid DLC? : My post on "The Elite" / the idea of spending money/going the extra mile to get WR (if you want VC any% WR, you need to buy a computer and buy a copy of the game...so many more examples...)

Does anyone need reminded about the use of SSD???

This seems so clear to me. I'm starting to wonder how some people are seemingly not seeing the logic here.

In regards to the DLC being in an update on PS3 and not on Xbox 360, have a look at this news item on Skullgirls, which had a similar "patch size" issue: http://shoryuken.com/2013/01/08/skullgirls-xbox-360-patch-delayed-due-to-size-limitations-four-to-five-dlc-characters-originally-planned/

On PS3 their update was about 500MB, but on the Xbox 360 they aren't allowed to do this; I guess they have a size limit. I imagine this is the reason why the DLC for GTA5 is separate downloads on the Xbox 360.

This is all just me taking a guess here, but it makes sense.