Some hotels are family-friendly. That is, they have a pool, maybe a games room, a children's playground, things for children to enjoy. Others may not be so child-friendly, but all hotels have other guests who expect your children to have themselves during their stay.
If you have a child involved in travel as hockey, basketball or football, you know that you spend a lot of time in hotels. There are games, there are tournaments and probably the entire team (if not more teams) are all located at the same hotel. It gives many children. It's great because you're going to hang out with the other parents, the kids are going to hang out with their friends and camps, but there should be limits to what the kids can do in and around the hotel.
For example, no other guest appreciates a gang of children who run down times that shelter on the top of their lungs. If you do not let your children run around like home, why are they doing it in a hotel? Another thing that marks other guests is that they quiet times are not maintained. Just because you're away from home does not mean you can always act out of the day or night.
Being in a hotel is freedom, parents can go to the restaurant or the bar while the children go to the pool, but it is also difficult since children should always be monitored around water regardless of their age. Even though parents change the pool duty, it's better than no supervision at all. Ideally, children should behave properly in the pool area, meaning no running, no diving in low water and compliance with pool rules. The same applies to the gym or fitness center if the hotel has one. This is for all guests to use and if your child has a legitimate reason to be there, watched then it's great, but having a lot of kids hanging out in the gym, annoying other guests is a no no.
For the most part, children and hotels are a good mix, and families are aware of the rules, the children are polite and calm, and all is good, that's when they are allowed to drive crazy that the problems arise. Nobody wants to be the one who gets kicked out of a hotel so hide the rules of fun for everyone.