> The lifetime of a company has been getting shorter and shorter for centuries.
Really? Because Apple was founded in 1976 and I'm guessing they aren't going anywhere. Google was founded in 1998 and I don't think they're going anywhere.
Your assertion is really flimsy, and I think based on seeing a large number of mismanaged companies that flare up and die quickly and then concluding this is normal or even unavoidable. While it may be common, that doesn't mean it's what has to happen.
Rovio took their success and drove it into the ground. They absolutely saturated the market, coming out with new Angry Birds games and tie ins almost constantly and flooding store shelves with very low quality (and in my area, often dingy) plush animals, further lowering public perception of their brand.
I'd argue that if Rovio had been more judicious with their successful IP, that public interest in it wouldn't have disappeared so completely.
You seem to be arguing that the fade was unavoidable since Angry Birds is just a game where you launch birds at pigs with a sling shot. But that doesn't mean the follow up games needed to be. Super Mario Bros was just a game where a guy jumps on things. Now I'm not really saying that Angry Birds was necessarily an IP with as much legs as Mario, but I think they burned it down.
Rovio chose the short term, maximum immediate profit path, and now we're seeing the result of that. Zynga did the same thing. When you go all in immediately, and don't think about what is best for your long term, you burn out public interest in whatever you have to offer. When you don't take the time to make what you're putting out compelling, people will start to conclude everything you have to offer is just going to be more of the same. And they'll be sick of it.
This is not the only path available, and asserting that it is just the way things are now is ridiculous.