Nathan Phillips’s review published on Letterboxd :
This calls to mind something Hitchcock said to Truffaut about the screwball comedy he made as a vehicle for his close friend Carole Lombard, Mr. and Mrs. Smith: "Since I really didn't understand the kind of people who were portrayed in the film, all I did was to photograph the scenes as written." Hal Ashby functions here as a sort of glorified director-for-hire transmitting Warren Beatty and Robert Towne's supposedly satirical comedy of class-conscious promiscuity set all too hamhandedly against a tumultuous political backdrop, and it doesn't seem to me he has any grip at all on the person Beatty is so incessantly trying to make us care about or on the evident issues in his life -- sex, failed bank loans, but mostly sex -- and as a consequence neither do we. From what I remember of the Ashby biography I read a few years ago, Beatty was really the dominant creative voice here, and it clearly shows even if Ashby's keen sense of time, place and youthful abandon is also apparent in how he's able to make a posh hippie shindig look like the most thrilling party since the one in Chaplin's A Woman of Paris. But does Ashby really believe in Beatty's message here? Moreover -- and more importantly -- does Beatty? The script is apparently a sort of after-the-fact hit piece on Charles Manson victim and "celebrity hairdresser" Jay Sebring; Beatty stars as a workaholic philanderer trying to start his own hair salon while juggling approximately four to seven women at any given moment. Ashby's own sensibility, of a level of affinity toward the outsider often verging on the sentimental (Harold and Maude) but just as often attaining genuine gravity and pathos (The Last Detail), is completely out of place here in a bitter assault on a man whose treatment of lovers is depicted as borderline sociopathic regardless of whether there's any sincerity to what the screenwriters are trying to say, if anything. The dramatic irony and feeling of impending doom you get from watching a bunch of petty priveleged types get their many fuckings tangled up on the day of Nixon's election is likely meant to evoke Rules of the Game; but whereas Renoir was unable to commit fully to his more acerbic leanings because he liked his characters too much, the political content in Shampoo feels like a cheap kitchen-sink addition to try and beef up a facile story, and it doesn't help that neither the character Beatty is playing nor his performance have any sense of depth or substance. If that's meant to be our takeaway, why does it feel just as phony when we're told at least twice that he's constantly having a great time as it does when he breaks down crying at the realization that he's wrecked an opportunity at long-term romance (a pretty difficult turnaround to trust, by the way, both because he doesn't seem the type and because his epiphany seems to come from nowhere)? Beatty hasn't the sophistication as either an actor or a writer to make these subtle little beats land in a way that gives the story much reason to exist, so this turns into another Blow-Up or Wolf of Wall Street -- an empty-headed scold that indulges in the frivolity of a man-child then expects us to indulge equally in its condemnation of the same behavior, which seems especially hypocritical coming from a celebrity like Beatty who attained so much of his early 1960s notoriety as a constant womanizer.* At least if the film had ended with some nod to its inspiration's violent death, exploitative as that may have been, it would have suggested some semblance of a point.
Ashby was one of the most repeatedly stunted directors who might otherwise have been truly great, and you do get a sense of his hand in play in terms of his work with the cast here -- he gets powerhouse performances from the three major female actresses, Julie Christie, Lee Grant and especially Goldie Hawn, who is brilliant here as the long-suffering "official" girlfriend (it may be her best performance apart from The Sugarland Express) -- and whenever he's permitted to focus on the bluster, misery, wide-eyed wonder and pain of Jack Warden's tycoonish Lester, an oblivious husband with ample money and power to throw around who despite the clichéd imagery suggested by such a sketch actually feels like a three-dimensional character at various points, but you know what those moments really did for me? They made me want to watch Richard Lester's Petulia, a deeply soulful film that gets the vast cultural disconnect and generational divide of the late '60s actually right, whereas Shampoo is a fake countercultural treatise that says nothing. A+ ironic use of "Wouldn't It Be Nice" though; I bet that was purely Ashby.
* The nursery rhyme from MAD Magazine -- "Warren Beatty had a sweetie, dazzled and bewitched her / Warren Beatty kept his sweetie for a week, then ditched her" -- is funnier than anything in this film.