Why do grandparents always think they have right to grandkids?

their kids are gone, grown up, moved out, and they see the grandkids as an extension of themselves, that their family will continue even when they are gone. they also don't have to raise them, so they can "spoil them and send them home". yes a lot of grandparents seem to think they deserve the right to the children whenever they want, which is totally wrong. a lot of grandparents are probably going to be a bad influence on the kids, especially if they were irresponsible as parents. a lot of grandparents seem to not be able to see their kids as grown up enough to raise children so they think they can in whenever they want. i don't think a lot of the grandparents rights cases actually win in courts, but i have never really looked into it. people can judge you, but you have your reasons for keeping your kids away from their grandparents. if it is just because you don't get along with her, that is petty, but if there is more reason than that, well your kids safety is #1 priority....