I'd point out that a "spendthrift trust" is not necessarily limited to a situation where the beneficiary is reckless with money; it may be that he/she has a lot of debts that may result from a business failure, or a divorce, and may have debts that can't be discharged in bankruptcy.
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I just filed an initial return for a such a trust, the beneficiary of which is anything but a spendthrift. But he's bankrupt in everything but name, with debts including:
*Taxes
*Unpaid wages from his business that went under
*Past due alimony (not only can't he get discharged but his ex-wife has hauled him into court twice to have him held in contempt for not paying.)

So with the recent death of his father, rather than receiving his share outright, his share of the estate was put into a trust for his benefit, which reads pretty much like a spendthrift trust. His father's revocable trust was amended recently to anticipate the need for this, knowing of his difficulties.

Bill