I don't think there's anything specifically stated (or atleast nothing that I can recall). I can however see the public perception of tattoos depending heavily on who is viewing them.
Staunch traditionalists may view any tattoo as a bad thing, where as the more liberal Kuritan might have no problem with them. With the revealing of the Ghost Regiments, and the part that they've played since the War of 3039, I can see a wave or two or three of people getting them, perhaps in a form of defiant counter culture.
There's also the question on if people can tell the difference between a Yakuza tattoo and a 'normal' tattoo. Would a person react the same way to a fully body tattoo as they would to a tattoo of a `Mech company logo on the shoulder? Probably not.
So like many things in the Kuritan culture, the answer probably heavily depends on who is doing the looking.