See you need 50 words and often users would use random words which could be considered spam like this- jd d. B g g g h. H h h h. H h. G g. G g. D. S s d. D d f f. F f f f
And thats why.
If you can give your argument in less then 50 words then it isn't substantial. If you really type 50 words or more to prove your point then you shouldn't be allowed to debate on this site. If this filter is remove then it clearly will be abused and trolls/idiots will be putting one word/sentence arguments and so on. Also real mature spamming to be able to by pass the 50 word rule.