I wonder if they were manufactured abroad, somewhere where English isn't widely spoken.
When I have been to China, there are lots of backpacks, T-shirts etc that say the weirdest things in English. I think it's just a script that's seen as "cool", and people can't translate the actual words. (Similarly, here, a lot of the T-shirts made by places like Superdry etc. that were popular a few years ago with Chinese/Japanese kanji on them actually said complete nonsense).