If I were in charge - that's a scary thought, isn't it - I would probably appoint a couple of moderators to each of those underserved boards. For example nutildah and DireWolfM14 for P&S, LoyceV with o_e_l_e_o for BD/Press, dkbit98 and Lucius for Croatian boards, mainly to punish them all for complaining so much

but also to give a bit of a proactive push to clean those boards instead of waiting for reports, which could be a good deterrent without banning. And I'd hope that having two mods work out some sort of agreement between them could help with the inevitable bias accusations and moderation complaints. If they start slacking a year or two from now, pick someone else from active users.
I’m just an occasional guest on the Croatian board so I don’t even consider myself nearly qualified to be a moderator there. In addition, there are other much more active members who are suitable for the job, if it ever happens that the admin decides to give someone a chance to moderate that board. It seems that on this forum it is much better to come to terms with the old rules than to try to change something for the better at all.
It's mostly a lost cause, unfortunately. In my opinion Bitcoin Discussion should be the most important board on this forum, but it's virtually useless now.
I have already read an almost identical statement several times, which only confirms that some people just give up before others (including you). Such statements only make the situation worse by letting others know that they should leave that board to spammers - because if LoyceV says something is a lost cause, then there is no point in arguing.
Believe me, I'd love to not have to ignore Bitcoin Discussion--it should be the most interesting and important section on bitcointalk, but the reality is that it isn't and hasn't been for years.