Most of us are thankful our parents took care of us and do love them. I recognize that it’s not everyone but I think most kids don’t want to see their parents suffer.
If a parent starts with a home bought by the grandparent and dual income and a lot of money, and end up not having a pension because they spent all the money on holidays and multiple homes and zero investing, would you feel like you need to support them?
I feel constantly conflicted, the previous generation started with way more and wasted a lot more and now we are called in to support them, affecting their grandchildren? I don't think that's ok
People with irresponsible parents often end up feeling less responsibility towards them. People with responsible parents often feel more responsibility towards them. Often, the irresponsible groups are suffering more consequences too, which adds to the bitterness.
Of course there are other permutations, since life is full of so many uncontrollable factors.