I think maybe to 'keep up with the times', swap hostesses should specify in the 'rules' whether or not embroidered items (blocks, mug rugs, doll quilts, etc) will be acceptable as part of the swap. That way, everyone who signs up would be on the same page.
It'd be no different than saying beforehand whether or not tying was acceptable in a swap of 'quilted' items. In reality, a person's like/dislike of embroidery on quilts only has a direct effect on them if they join a swap.