The entire concept is ludicrous

In the 1930s, this scenario absolutely was recognizable to people. While it is true that a couple of the children are reasonably well off and so perhaps it's a bit of a stretch in that sense, before the Social Security Act, old people were entirely at the mercy of their children or whoever would take of them. And even the SSA did not cover old people immediately after its 1935 passage. There were old homeless people all over the country. It was this sort of thing that led to the mass movement around the Townsend Plan that forced FDR and Secretary of Labor Frances Perkins to move more aggressively on real old-age insurance, because a lot of people were demanding more. For an audience in 2016, this scenario might seem bizarre. For the 1930s, it absolutely was a relatable story, down to its more depressing details.

I think your comment is ludicrous .. lol .. just kidding .. From what I know this can happen in the best of families .. My cousin's mother lives with him and his wife for two weeks out of the month and the other two with his brother .. she is 99 can still get around and do everything that she needs to do .. but neither brother is happy with this arrangement .. and one daughter is law is just horrible to her .. my mother died in 07 and I would give anything if she were back and living with me .. I told my cousins that one day they would regret feeling this way .. Believe me this happens in the real world .. sad , but true .. Happy Holidays to you and your family and peace to you .

It absolutely is not ludicrous and what you saw as ludicrous is the point of the movie. Read the opening quote about the aged and the young and the canyon that can't be bridged unless you adhere to "honor thy mother and thy farher". The children are living their own lives and only want to accommodate themselves as they don't understand exactly what the parents are going through, nor do they care; they are mainly concerned with their own life styles. Sounds a lot like today to me. This movie is just as if not more relevant today. Also, the apartment wasn't that big; there were no spare rooms- just 2 small beds in the granddaughters room and they weren't well off. Anita taught bridge to well to do folks to meet the bills. It's implied they wouldn't have a place to stay otherwise and to Anita I'm sure that's absolutely true. She certainly wanted to maintain her social standing not just for herself, but her daughters as well. She insisted her daughter bring her friends by the house and granny talked them off. It's completely plausible that they'd run her off just like they did.

The original post was way off base in the assessment of the "massive house" with the "ballroom," which was actually an apartment no more than 2/3 the size of the one on "Friends." If you're that far off about the massive house, ponder what else you might be wrong about.