extraordinary - Oh, undoubtedly, they think they are generous. But they're only generous to themselves! Still, as others have pointed out, that's their prerogative.
Gentleness -yes, my baby is too young to know, which I suppose is why I've taken it personally.
I guess this thread is not just about the lack of birthday present; it's all about tricky family dynamics, as you point out.
I used to get on better with them before the baby arrived. I was always aware of the family problems, but I wasn't really affected before. As soon as the baby was born, I got sensitive. Maybe it was partly post-natal hormones.
MIL came to the hospital when baby was 1 day old. My husband said "What do you think of her, Mum?" She replied "Well, the top half's OK. The legs are a bit strange". (i.e. they were still bendy from the womb)
When I got out of bed and sat beside her to show her the baby, she said "You should have a shower." (Maybe it was true, but not a tactful thing to say to someone who has just given birth)
She then said to me, still in hospital, "Oh, her skin is like mine. I do hope she has my skin; that would be much better than your pale skin". (i.e. my skin. Anyway it turned out the baby had a touch of jaundice.)
When she was 6 weeks old, MIL said "She's very fat, Seoladair. Are you feeding her too much? You should ration her milk". (My health visitor said the idea of putting a 6-week-old on a diet was not just stupid, but dangerous".
The next week, baby and I were staying with my parents, and ILs rang me, ranting that I should be with my husband "being a proper wife, and doing his laundry and cookery for him" (My husband was very relaxed about me being with my family, and was actually enjoying the break from babycare!)
I am just venting now, but this is a snapshot of the past year, which is why I am tense about them, and possibly over-reacting to the lack of birthday present for baby.