So what if the size is tripled? There are games on the PS3 that are more than 4 GB in size.
Now yes you could argue that is a problem for the 360 but...correct me if I'm wrong, but isn't the biggest allowed size of a digital download game on 360 4GB? How big in size would the customization options be if they're gonna exceed 2 GB?
There are different limits for XBLA and Games on Demand. XBLA has lower limits, hence why the customisation DLC exists.
Also, no offense, but by complaining that the items aren't included as part of the game, you are in effect doing the opposite of the people who hate on companies for on-disc DLC, and as such you're making a situation where the developer can not please everyone. Besides, there are more important things than the items that you should be more concerned about. Like the netplay for instance, considering that will be the only way that most people will get competition (to start with at least).
Fortunately for us, one of the key figures in the US VF scene, L_A (who has the game already and was playing Haunts last night), said that the netcode was better than vanilla's, and that was playing an opponent 400 miles away and while Haunts was streaming. That's rather promising to me.