Is my grandma right or just old school knowledge?

I have a five week old baby boy and he loves lots of cuddles and comfort. I'm breastfeeding, not exclusively but he also likes to use my boob as a dummy.

My grandma keeps moaning at me saying " don't keep picking him up he will get use to being on you and being picked up". I'm not sure if this is just her old school views or wether it's true?

I'm not just going to leave him crying or fussing. His very little he needs me! I don't care if I cuddle him to much babies need love and comfort.

My point is, is this true? Do babies start picking up "habits" at this age like she says??