I do not believe anyone in this thread stated that trusts are prohibited from issuing 1099-MISC forms.
The fact remains, however that trusts do not "issue 1099-MISCs all the time for expenses paid out of the trust" (I have no idea how that statement could be either verified or corroborated as the typical trust is private).
Regardless, it is clear that the IRS intended the form to be used only for trade or business reporting with extremely limited exceptions.
Trade or business reporting only.
Report on Form 1099-MISC only when payments are made in the course of your trade or business.
