I know I send bad trade requests on a regular basis, I don't do it on purpose, but it happens. I should get better about checking what i'm sending to who, but mostly I just check the pins i'm willing to trade. Now I don't go offering a HM for a PODM, but still. Most of the time people ignore my requests. If I get a "no thanks", I also check what was offered and apologize if it's called for.
I get dumb requests all the time, but mostly I figure they're doing the same thing as me. Now, if someone was going to send me a message like that, i'd be annoyed.