Actually, it depends on the purpose of the post, if a person has the purpose of explaining something in detail at once, then he has to make the size of the post a little bigger. Moreover, many people usually keep the length of the post a little longer to avoid spam, but that doesn't mean that a simple short two-line post is not qualityfull. Sometimes even a two-line post can contain a lot of important informative information that can't be found in an eight-ten line post.
That's a real truth, But I don't think it's right to put everyone in the same queue. Yes, there is a minimum character requirement for signature campaigns, but you don't need to make a big post to fulfill it. The requirement is fulfilled in two or three line posts. However, there is a report option for those of you who think there is a problem with the post, and there is no guarantee that the big post will not be spam, you can always quote the posts in this topics.