Some writers want to express themselves comprehensively. They want to write it the way it flows from their mind, which is why their post most times are long. I am also guilty of this offense. I will have to improve my expression in the English language and also consider the length of my post because I will never want to be called a bot.
expressing oneself doesn't really mean writing some bunch of words to convince the reader, there are few words which you could just post that carry heavy meaning at same times summarized all you wanted to say.
When they said of spamming, it doesn't mean writing a very short words that results to spamming, you may write a very long and lengthy words but doesn't carry meaning would still results to spamming.
There are even times in which you can just directly construct the point of your reply using short sentences only as long as your message is clear, concise and it is readable you are already good to go. I am well aware that there are several members here that has very deep choice of words or their vocabularies, and it is not fair if we consider and judge them as bots. As for me personally, the meaning of "constructive post" doesn't mean how many characters you use or words and even grammars, it is how you convey your point of view since this forum isn't created for constructive criticism alone but also to provoke discussion and spread knowledge to one another.