“Subject” field always existed in DW, and in LJ before that, and in e-mail before that. There must be a reason, so if you say it should be left blank I’d like to know it. I don’t mind following the rules I understand.

“Trolls use it” might be a reason, if prepended with “only” or at least “mostly”. Trolls also use letter ‘a’, it does not mean others should refrain from using this letter.