The thing is, standards are pretty much set….at least in terms of laws. The fact of the matter is, many programs are edited beyond what is necessary by law. This is why editing often seems inconsistent. What you have to remember, too, though, is that more than simply a means of communication, television is BUSINESS. The goal is to get as many people watching your channel, and your shows (and therefore, your commercials) as possible. Not only that, but you want certain target audiences watching them. If your show runs with commercials for action figures, you don't want to market the program to geriatrics.
As you yourself mentioned, the feelings of some parents as to what is and is not suitable for their children varies; as my own example shows, we have kindergarten-aged kids watcing Naruto (and "worse" in some cases) in our house. I don't think this is because my parents and I are irresponsible, I think it's because we know what our own family members are capable of accepting.
Now, imagine for a moment. You are Al Kahn, or some other kids TV mogul. I know, it's kinda unpleasant, but bear with me. Now, you are trying to target, let's say, the 5-11 crowd with a new program. You can either edit it considerably, in order to get the widest amount of acceptance among younger audiences, and therefore increase the show's revenue, or you can only edit it as much as is necessary to get the rating you want (which isn't necessarily much)...and in doing so, break yourself off from a considerable percentage of the audience. Even if it's begrudgingly, you've got to admit which of those is better business sense. 4Kids makes more money than ADV Films for a reason.
In a way, it's also more than good business sense, as well. I've harped on this point before, but it's worth repeating: of the miniscule percentage of shows that do get hacked up for a TV release, most of them were originally tailored to younger audiences as well. One Piece is a "kids' show". That's part of its charm. In my eyes, all the hammer-guns in the world won't "butcher" a show more than taking it away from the friendliness and atmosphere it's supposed to project. Edits can change a show's FACE. Poor marketing can change it's SOUL.