How desperate would it be to ask for merits. If we were going to put our shoe in their shoe having trouble in earning merits then probably we can understand why it let them to decide to do PM to beg for merits. We cannot judge directly to users that are doing this. Probably others just wanted to make some abuses by merit farming and others may have done it as mention by other users that they are near to rank up in into new title and they can't just wait instead they ask for it for them to rank up. Other than that probably they are kids having trouble to formulate sentence but learn to do cryptocurrency but their only problem is how to make a good rational statements that could let them earn merits. As we all know adults and young once had different level of knowledge especially in reasoning out where adult could come up a good reason due to past experiences while those kids don't have.
In that case, if ever I will be able to encounter a PM asking for merit then only I can do is to scan for his posts history and see it if I can give even at least one for him if there will be a post that for me worth it to reward merits. I will not be greedy for it is only a merits and who knows that by giving him a merit the user may able to join a campaign and earn which he really intend in joining here in the forum.
Let us not judge users directly basing on how they act but I think for me in my opinion it is better to check first and ask why he needs the merit and if he is convincing then as what I have mention I will check the posts history to reward merits. If none then I can inform him to make a thread or his best posts for me to rewards him the merits. And if there is really no chance of improvement then out of pity I will still reward him with merit. We can see him a trash user for now but maybe in the long run he can grow as a good user. Let just help them instead of making fun of them. I had been into that phase of my journey here in the forum and had been laugh by other users as well but I still manage to grow activity and earn some merits just recently.