The only solution seems to make less merits for ranks. 1000 merits for legendary really seems impossible.
Legendary rank should be a very very difficult rank to earn to start with. If a person consistently makes great and in-depth content, 1000 merits might be nothing. Also knowing that a single great topic alone can earn you 20+ merits or even more, depending on how good it actually is.
They may not deserve merits but I have seen really good posts without merits. You may be generous but other people can oversee posts or just don't care.
I don't agree with that. I've always seen merits of good posts; you might be referring to posts that are technically good but are answers that are commonly replied like
"your best choice would be to use a hardware wallet because etc etc...." . There's enough enough sMerits in circulation for the good posts out there.