As for historical and cultural significance you have a point but we may also expect that some altcoin iteration becomes revolutionary. And maybe someone is interested in collecting the original altcoin, the legacy altcoin that started everything in the future.
There are hundreds of altcoins created each year, and almost all of them die rather quickly, and not a single one of them has became truly revolutionary, not even Ethereum. And then, you should also keep in mind that cryptocurrency is fungible, so even if you have a coin from early blocks, it stops being such when you transfer it to someone. And this thing with putting coins out of circulation does not happen with every altcoin. So, overall the chance that you can get some extra value from altcoin being collectable is astronomically low.