Since there is no way of sending sMerits in self post, it's forbidden to send in alt too. Sending merits to alt should not be encourage here. It is counted as abuse. DT member would tag those users.
That's pretty solid logic if you ask me.
And while I think it's certainly abuse, I don't believe Theymos wants DT members tagging members who merit their alts. DT members have done it in the past, but in the past few months I don't think a lot of merit-swapping deals have gotten negged. It all depends on how blatant and extensive the abuse is and IF a DT member feels like giving them a neg.
As for myself, I've pretty much bowed out of tagging merit abusers. There is too much subjectivity in these cases and too many chances to erroneously neg a bunch of people all at once. I'd much rather stick to the relatively black-and-white offenses of account selling and such.