I like all colors being released simultaneously as well, but while I'm by no means rich, I don't have an upper budget for card purchases, and sometimes the price of some of my carts or KS backings from one campaign take even me a bit aback. If a campaign had 4 colors, and each one was $13, that's $52 for one set. Not chump change, and that's only for one set. For collectors, we often like to have multiples. Three sets at $52 is $156, and that would get anyone's attention, and be completely out of the realm for many buyers.
I bought so many of the Federal 52 editions that I was more than happy to see the next deck in a new campaign. I'll get a bunch of those too, but it will be weeks./months later, and that's easier to digest. Deck reboots spread out give many more folks the opportunity to buy without having to give up rent or food, so I get it from that perspective! I usually get in, on average, about 6-8 decks a week. If I bought a decent quantity of a limited time (like a KS deck with no after-campaign sales available) deck, I would probably think twice (or more!) on backing/buying some others just to keep from getting (more?) out of control. I can see it being a better option for many.