It's all about money, and a fad as psychodog stated. It's the same with so many gadgets for this and that which fill the pages of catalogs and websites. I'm sure some of the things work OK and could be useful, but if I had to have everything marketed that attempts to convince hunters they need it, in order to accomplish this or that and in order to successfully hunt, I'd need a pack mule - or maybe two, not to mention a rather large wallet filled and running over.
Now that we are on the topic, and in my opinion, a lot of the camo on the market is pretty much useless as far as real camo goes, but it's pushed and sells well.
Some of the best camo, for my neck of the woods anyway and most of the east, never really got a start, and it's good stuff. One example, Forest Floor camo is really good stuff, but about as scarce as hen's teeth. As well, Advantage Timber was a good one, with all the shades of leafy colors. Both blends well with the fall leaves here in the mountains. Why is it no longer made? It probably never had a good marketing start (Forest Floor), nor big name pushing it. Advantage Timber was "the" thing at Cabela's for quite a while, then suddenly disappeared literally from one season to the next, and Realtree took over in a big way. Other brands like Mossy Oak made it big and continues to somewhat, but most guys I know will tell you it's too black and dark colored for most places they hunt. It probably works fine in the forested swamps of the south, but it apparently has such a big marketing campaign that a guy would think it's super camo for use most anywhere.
That's just the way it is. But, you would think that once a great camo pattern is found, that it would continue to be available since it is so good. Such is not the case, since something new has to come about to continue to get hunter's money. I suspect the Zombie stuff is one of those things. It will most likely run it's course, and then something else will come along.
Maybe some of you remember when Spencer's Gifts sold pet rocks. That's right, pet rocks. When I first saw one, I told my wife out loud, "man, that's nothing more than a creek rock." but, the sweet little rock was nestled in a box of fluff or straw, given a cute name, and sold for quite a bit of money, as I recall $10 or more and that was back in the mid 70's. A lot of those city slickers jumped all over them. If only I had of known at time time, I could have got a ton truck full of creek rocks. But, 'twas not my idea, so some other guy had the good fortune.