I agree, but the issue is the necrobumping post rarely is relevant.

In some boards, such as Technical Support, necrobumps are usually fine, because it is from someone having the same issue as has previously been discussed. It saves having to open a new thread and rehash all the answers which had already been given, and gives a base to build on with new suggestions, help, or information.

However, in boards like bitcoin discussion, necrobumps are almost always spam. They are bumping megathreads with one or two line answers which have already been said somewhere in the previous 10+ pages. No one is actually reading these replies, but once the thread has been bumped back to the front page, other spammers descend on it to also boost their post count.