Graduate has been being used since the early 19th century as an intransitive verb, and is defined (without censure) as such in the first edition OED. Fowler's first MEU has nothing to say about it. Merriam-Webster's DEU mentions that the controversy began in the USA in the late 19th century by a couple of prescriptivists.

[Fixed typo.]

Ceci n'est pas un seing.