I dunno. It seems to me that every few years there is a 'rebirth' of skirmish level games. I just think that they disappear for a while. Old ones die, new ones take over. When I got started in wargaming, it was Battletech. There were typically only four or five models on the table. I started with the big army games because of Necromunda, which was skirmish level. I left the hobby for a few years, and got back in due to Mordheim and Bloodbowl, which were huge at my LGS. Then a lapse. Now, Bloodbowl has come back into favor at my new LGS, and Malifaux is becoming the next thing.
The problem with skirmish level games, though, is that they have such a small base. With just the initial buy in, you have all you ever need. There's often no reason to buy more. That's what keeps the big dogs in business. You will always need more or different giant troop units. The problem with skirmish games is that if you buy all the different options, and even spam them all, eventually you have it all. Then the company is sitting there with a bunch of models people won't buy and they go away. I think that is why many games that start out as skirmish level (40K, Warmachine, etc) and grow to army games is for that very reason. It's hard to stay in business when everyone who wants to play has all they need. Rules don't expire (I'm still happily playing D&D 3.0 and haven't spent a cent on D&D in years!), and models only need replacement if they get lost or a better one comes out. So that's what I'm dreading is the day that I have to have a big box of plastic gremlins for my Som'er Teeth Jones crew, or they disappear because there are no sales. Cause a mini isn't just for today, its forever.