While I do agree with your Heinlein comment based on the couple of books I've read by him, I'd advise you not to lump Lois in without actually, y'know, reading the series in question (and I cannot guess what book you're talking about from your synopsis -- if it's Spirit Ring, please try again -- that is probably her weakest book, bar none).

Onyxhawke (a big LMB fan, btw) is being funny in his criticism of her. The Betans are not actually held up as an ideal but rather as yet another extreme to which her universe full of distant-future humans have gone to.