No, it just means Mary's show had to make it on its own, while the spin-offs had the parents series to help them set sail with a built-in audience.
Interestingly, the first season of MARY TYLER MOORE comes off as a bit loud ('60s comedies filmed in front of a live audience were often delivered like a stage play, and MARY inherited some of that initially) and the early jokes at Ted's expense often just came down to his mispronouncing things. (And it's hard to believe today that the simple satirizing of the revered silver-haired newsreader image was hysterical at the time, just because the show had the chutzpah to do it). Yet, in 1970, the show came off as incredibly fresh, given what else was on TV at the time. There's a deeply melancholy flavor to Season 1 that I still find rather poignant, in keeping with the cusp of the '60s/'70s, even though the show is just finding its way.
A good group of writers and producers, the characters on MARY soon became more nuanced and developed, and the program barely ever made a misstep during its seven season run (earning a record number of Emmys and nominations) and was viewed at the time by critics as the closest to perfect a TV sitcom had come, at least up until that point and well-beyond, and I tended to agree. And even then the series seemed a '70s period piece -- not so much in terms of topicality (as MARY mostly avoided the politics of, say, ALL IN THE FAMILY and many of the Norman Lear shows) but in tone.
The spin-offs, on the other hand, were spin-offs. RHODA started out with a bang, but the network wanted Rhoda married by the eighth episode. The wedding garnered huge ratings, but it doomed the show by shoving the lead character into a miscast marriage (David Groh was okay, but not the right actor) so Rhoda's adventures as a swinging single in NYC were sabotaged -- at least until the producers divorced them, and then Rhoda's delayed sojourn prying disco era lounge lizards' hands away no longer worked either. So RHODA often didn't know where to go. And, as so often occurs when a wise-cracking sidekick gets her own show, the edge is removed once that character moves center-stage... I think PHYLLIS was frankly too neurotic a character to work as a lead star; the show's ratings dropped fast and also didn't seem to know what it wanted to be. LOU GRANT, of course, was a drama and pretty well done (although, oddly enough, I missed it most of the time).
But I've run across a number of intelligent-but-predatory people who still
despise the MARY TYLER MOORE SHOW with a passion -- they seem to gutterally resent the fact that such a vulnerable, spasming character like Mary Richards would be the sympathetic, central role, and feel Lou Grant should or ought to smash her like a bug in the first episode... Which is --- fascinating.
