You'll see the same thing with japan randomly using english words (like one word of a song), though afaik they usually use them correctly (but very awkwardly).

But the chinese tattoos, and the english words, aren't meant for those native speakers to see. The tattoos are meant for other english speakers to see, and the words are meant for other japanese speakers to hear. They're not meant to be understood, so much as just being visually/audibly cool.

It looks good, and it sounds good, and its in an environment where almost no one will understand it, so it really doesn't matter if the content is correct. The idea is sufficient.

Now of course, if you get a chinese tattoo mispelled and move to china, you'll look like a bumbling idiot. Its the same as being a native speaker and mispelling it.

The context/environment matters, when deciding how important that mistake is.