It's not offensive "too you." That doesn't make in non-offensive. I can't believe I actually have to say that. I can't believe anyone would not understand "at all" why "kick-butt" could be offensive to someone on an elementary school campus. I can't understand why anyone who has every been in a 3rd grade classroom couldn't see the distraction a kid with such a shirt can make. The word "Butt" doesn't offend me personally but sorry, I like to consider the feelings of others. I like to show a little class in public and teach my kids the same.
How is school stringent on dress codes? They are SO basic. Don't wear flip-flops because duh, you have recess during the day and in elementary school, you don't dress-out. Don't show underwear... oh dear, those poor kids have to wear a *GASP* belt or god forbid, a tank top with a little thicker strap. Oh man, you mean I can't wear that one t-shirt I have with a marijuana plant on it? But I only have 15 other shirts to choose from! Wow, we are just putting SO much pressure on our kids to show a little manners.
This is so ridiculous. Go ahead. Fight for the right for your kid to wear a shirt with the word "butt" on it. I'm going to put my energy towards something more important lol.
I think it is nice for kids of all ages to have self expression - as long as it is not offensive to most moderate people. "Kick butt" is not offensive.
I like to flip this point around - kids have enough rules to deal with particularly at school (many of them necessary but some arbitrary) without micromanaging what they wear.
I do not think the school/office comparison holds up. Where to work is optional for many people (indeed I know people IRL who won't work in certain places due to having to wear a suit or uniform). School is not optional for many youth. If school is optional, or if there is an option of a school with less stringent dress rules, then maybe, maybe, it is OK to say "this is the expectation here." (although I still do not think it is the best idea)