The loss would be a shame, but calling it a "sick tragedy" is a bit of a stretch. Unmaintained, the data will get stale fairly rapidly, and it won't take long for another service to step in. There's a vacuum here, and someone will fill it.
Seriously? Somehow I doubt the presence of or absence of lolcats and 4chan will make much difference to future generations.
We're already drowning in data. We need to start making some executive decisions about what's important and what's not. If it turns out we're wrong - we'll deal with it.
Find one and ask them how many parts of their body they'd pay to spend even ten minutes in the town square listening to the mundanities you so causally consign to the bit bucket.
There's more information there than you think, more than you can even see, because you are a product of the time that generated it.
I agree that lolcats, in and of themselves, are useless, but to say they do not have any cultural significance is a very big assumption. Don't you think that the popularity of such a meaningless meme is representative of some undiagnosed issue with society? I mean aren't you curious as to why certain pictures of cats are becoming more well known than leaders of most countries? Isn't it odd how such a simple idea is able to still amuse us as well as grow in popularity?
www.Historio.us is a great alternative. The free user is enough for me, but others can take a look at the pricing plans here: http://historio.us/pricing/