It's not the only one. Concurrency support ('synchronized') may be another one and I would see that one even more problematic.

Just recently I was hit by a runtime exception from a library which apparently decided that using undocumented unchecked exceptions was a good idea. The vast majority of open source libraries are not or poor documented, even ones which are used heavily (as in my case). In these, checked exceptions are a godsend as they MUST appear in the method signature.

For many programmers, exceptions just get in their way and they handle them poorly which is imho one reason for the bad reputation of checked exceptions.