Griefer's always like to destroy other people's hard work. Mostly because they can't design as good and they want to put on a show. Now if you want to destroy the building to maybe make something else than you can destroy it. And if everyone is fine with it, it cannot be called griefing.
I am completely against griefing, except for on servers that allow it, but I don't play on those much. This is mainly because I don't want to see all of my hard work destroyed, and all of my items taken. But if someone owns a server and wants to let people grief, that is the server owners decision, and if you don't like it then don't play on that server.
I think if a server allows it and those playing on the server are aware that it is allowed then all have made the choice that its part of playing. Personally, I would not do it and wouldn't want it done to me.
I get so mad when random people come in and destroy my stuff that I have worked so hard on. I have to agree that if I am building something then I want to have the option to destroy it myself, not have someone else ruin it. I learned my lesson and started building my stuff in single player mode so that way no one can touch it.
I don't think griefing bad, people make it a problem. They are probaly reporting the griefer(s). But if i get griefed i don't get angry. I just simply build it again. I don't think it's a big problem.
Griefing is incredibly immature and overall terrible. I don't understand people who spends their time destroying something that other people put hours worth of effort into. Some argue that we shouldn't get angry when something is destroyed because it's only 'a video game' and that if we want our creations to be perfectly safe we should build it on a single player.. but hey, maybe I should go around and hack people's websites for fun. Don't get angry, it's just the internet, right? Who cares if you put weeks worth of effort into coding the website? It's just the internet. If you want your website to be perfectly safe maybe you should just make it run offline! And if people want to see the website, they can just go to my house and see it directly from my computer! Amazing idea, right?
I think griefing takes a lot of the fun out of what could be a fun experience. Most of the servers have some sort of system where you have to be "approved" before you can edit someone else's work. However, I think that takes some of the fun out of it. I think it would be more fun if we could sneak into people's houses and steal some valuables or something, but servers can't allow that because griefers will steal valuables, burn down their house, then kill their pet sheep lol.
Trolls will always be there and that is the sad truth. Permanently banning griefers is the right way of taking care of this problem.