- why is the custom in Meta section to close the topics? I understand the intention to reduce the spam, but, however, I didn't observe this custom in local sections, for example, nor in other sections. If the only intention is to reduce the spam, why isn't this custom applied also in other sections?

I've been making an active effort to lock threads in meta once they have reached a conclusion. If anyone has any reason why the thread should be unlocked, you are welcome to request that it be unlocked, and I'll happily do so. But Meta is one of those sections that spammers feel that they can hide their spam, and be outraged when their posts are deleted under the guise of "this is supposed to be a special section about the forum!".