I don't have an issue with passing down a craft or trade, I worked for my folks at that age but nothing too major.. That said, anyone who sits in the chair and knows a 7 year old is about to tattoo them gets what they deserve..
If there's no labor laws being broken and clients are cool with it, who gives a rats ass, lots of generational tradesman and craftsmen start this early..
I guess if you're a tattooer that had to work their ass of to get an apprenticeship it could/would be frustrating, but we're all dealt the hands we are dealt, this kids hand happens to be with a tattooer in the deck.
At the end of the day, it really doesn't affect anyone but the people who let a kid tattoo them. I find it ridiculous that we have let price and explanation of price become a taboo and dare not discuss it but we are all up in arms about someone teaching their child to tattoo..