You're actually right on this one. Many altcoins have been outdated but yet they're still part of the top ranks. It will only be a matter of time until most of them get eliminated there and become a forgotten coin. To me, it's not about being updated or outdated on this market with their blockchain or what does the developer does. What matters to why they're retaining their position is because there's a strong sense of support that's coming from their community. That's why if it were not for the community, many of these altcoins have been dead long time ago already. But then, they're still alive and kicking and so they're staying to their current positions but just like in the past, many of them have became once a popular coin but now forgotten.
Exactly some altcoins are still popular even though they are outdated which is surprising. I think reason they are still popular is because of their dedicated community not because they are better or have newer technology. Crypto market has shown that a strong community can make big difference and that is keeping these altcoins alive. Even though they might not be worth much or offer anything new their loyal fans are keeping them going. But we have seen before that even popular coins can become unpopular and I think many of these altcoins will eventually become forgotten.