I agree. It’s not something I would recommend but there are cases, especially where committees are brand new or recovering from years of proxy harvesting, where it can help to get past the initial stages
That said, a strata manager can attend meetings and offer advice without having to be a member of the committee.
However, I would advise anyone who’s been told that the strata manager being on the committee is standard practice, to run a mile … and get another SM.