Not necessarily, more information is needed for a good answer. If grandma wants to give her favorite grandkid stuff...that isn't wrong. Many kids / adults love their grandmas more than their own mother. Now if said grandkid never goes to see her or do anything for her other than to ask/accept things from her then that is very wrong and they should be ashamed of themselves.
There is no simple yes or no to this. If there is someone who is just getting gift after gift then yes I would question it. However, my father-in-law has been placed in a nursing home. He can turn over all his assets and go on Medicaid, or he can gift some before going on Medicaid. Unfortunately his soon to be ex-wife has taken and hid the money, so there are no assets. My husband's grandmother knew she wasn't going to live forever and started giving her stuff away to whom she wanted to have it to prevent any miscommunications later.