I think I know what you mean OP.
I posted yesterday about DH's Mum, who has been absolutely awful for years, sending him a message to say she would like "a lovely text" today and going on to tell him what she would like that text from him to say. That's not all she wanted, but she decided this would be a nice extra.
She's always been very high maintenance and it has been known to happen in that past that if she didn't think her card or present was good enough, FIL would ring up to shout abuse at us and DH would go out and buy her something 'better', usually something she had already had her eye on and decided we could buy for her.
In addition, the card and present could be perfect (cards always had to have a long poem in them, preferably a poem one of us made up but if not then it had to be one of those Helen Steiner Rice epics of gushiness) but if we didn't spend precisely the right amount of time visiting her to hand all this lot over, we'd get a phone call half way home telling us she was in tears and we'd ruined her day.
The reason I posted about this yesterday was because I was telling someone about Mother's day 2007. We buried our stillborn baby four days before Mother's day and wanted to ignore the day in all honesty. MIL had said she didn't want to acknowledge the day because her own mother had died just over a year before, but changed her mind without telling anybody and we got a phone call with FIL ranting at us for ruining her day. When we pointed out she hadn't wanted anything and that we were having a hard time ourselves we were told that they had forgotten about our baby but DH was still expected to do something for his mother because she was inconsolable that all four of her adult children had 'forgotten' her and he should have known better.
DS spent his childhood being told he had to make her happy or she would have a breakdown and everyone would blame him.
This is the type of person I think the OP is talking about. Not everybody, just people like this. OP did say 'often the case' not 'always the case'.
And it's true in MIL's case, the OP is right. The whole family knew how bad it would be if she was unhappy about one little detail, so everybody went overboard to try and prevent the drama, not because they felt that she deserved a lovely day.