Interestingly, The Who were not at all well received there.
Well, they were well-received enough for Tommy Smothers to invite them to appear on The Smothers Brothers Comedy Hour later that year. But The Who were not yet the peerless live powerhouse act that they would shortly become. If you've seen their Monterey performance of "A Quick One While He's Away", and the version they performed a year-and-a-half later at the Rolling Stones' Rock 'n' Roll Circus, the difference is remarkable.
They weren't as well known in America at the time and the weekend was "peace, love and flowers" and they didn't represent any of that with their performance. Look at the faces in the audience afterwards and they're horrified. Definitely the wrong place and time for that kind of show. In terms of "what they do" it was great and put it at another venue, especially a year or two later, and it'd be much better received by the same crowd probably, but from the people I've talked to who were there, artists included, at the time it happened they were not appreciated by the majority. Revisionist history may tell a different story of course.
However, I do think that what they did allowed Hendrix to go over better than had Jimi gone on first and done his lighting the guitar on fire act. The audience was so numbed by The Who that they kinda warmed up to Jimi more and his antics seemed a more erotic version of The Who's destruction, which comes off as angry. That said, they were two great sets by two iconic live acts, but in terms of connecting to the audience The Who missed their mark with it at Monterey.
I think that's a fair assessment. The Who were indeed the antithesis of the peace, love and flowers crowd at that time. I recall David Crosby saying that, at the time, he was thinking, "How dare they break up a drum set." But later, at Woodstock, he said that he and the other members of CSN were thrilled to be there because artists like The Who and Hendrix were heroes to them. With Woodstock The Who became thoroughly embraced by the hippie subculture, which is interesting to me because I think The Who may be the only artist so fervently embaced by both the hippies and the punks.
One footnote: The artists there also loved the Electric Flag's set, that had them buzzing, but it was Otis who shook everybody to their knees. Easily the single most praised set by other artists I've ever come across (in part because so many where actually there, but also the performance itself).
From what I've read and seen, the most well-received set might actually have been Ravi Shankar's. Pennebaker even chose it to close his film. I don't think I could have endured four hours of that, myself, but the excerpt in the film is mesmerizing.