Ah, okay. I tend to skip all of the graduation episodes, they just don't hit the right notes for me most of the time. I just assumed it was more like what @Snow Apple said, she saw it as being 'independent' despite having a safety net.
It's pretty funny to me that Natalie would be outraged about her mom not supporting her, since she seemed to equate struggle with "real life" that she felt she needed in order to be a writer. Her ideas about being a writer were pretty much on par with Tootie's idea of being an actress, it was like they picked something in junior high and just went through life announcing that that was what they'd be, without ever really knowing what either one was about.
I wasn't bothered by her or by Andy because I liked both of them and found them funny. It added something to the show for me, unlike Shaun Cassidy's character, Pippa, Kelly the punk kid, or even George Clooney's character, which is really only notable because of what he would go on to become.
Mrs. Garrett's role in her latest seasons was not only diminished, it was all over the place. She's in school, she's got a friend accusing her of sleeping with her late husband, she's got some old boyfriend coming back into her life from Wisconsin, who I believe is a DIFFERENT old boyfriend from the one she ended up marrying and going to the Peace Corps with...it was all so disjointed.
There was a spate of episodes between seasons 6 & 7 that seemed like genuine standalone pieces and not part of an ensemble series. I'm not sure if that was intended to disguise the absence of Charlotte Rae, but the weirdness of those episodes hurts the show way more than no Mrs. Garrett would have, since she wasn't even close to being a focal point of the show by that point.
I do think the barbs between her and Blair were mutual and ultimately good-natured (though Blair was able to cross that line into sincerity more often and more believably, considering she's the more fortunate one in life, it makes sense that she could cross the aisle a little easier), but the chip on the shoulder part about Blair's wealth was annoying in the ways that she put her pride above all other considerations.
There's the example I posted earlier about her holding up the construction on the room that the 4 of them were building because she couldn't bear to even take a loan, but there was also the time that she lost her financial aid and didn't have a room at Langley. She refused any kind of financial help, but had no problem crashing on the floor of Blair's single room, inconveniencing her, and eventually getting Blair in trouble with the dorm board despite her being a paid up resident.*
*That dorm monitor bit cracked me up. I still want to know if that was a thing into the 80s, I think there was such a thing as a housemother or dorm monitor type role earlier in the century, but I have to imagine it had mostly become obsolete by the 80s. I had an extra bed in my triple dorm room when someone dropped out mid-semester and we had guests sleeping in our extra bed or all over the floor on a regular basis and no one ever asked/cared whether they were students or not.