It depends on the business owners and the actual tattoos you have. At the hospital where I work, one of the male nurses has only a few tattoos on his upper shoulder so you cant see them, while another male nurse has several tattoos that are visible along his arms. He also has dyed streaks in his hair and only a few piercings. His tattoos though are light-hearted, sentimental and a few are just cool designs.

Perhaps it's the nature of your tattoos. On the other hand, it's more than likely that some business owners were more offended than others and the tattoos weren't a major deal to them. They may point it out because depending on the nature of them, it's self-explanatory. Could you try to cover the tattoos up as much as possible when you go for an interview? You could wear a decorative scarf, button up a shirt, wear long sleeves but I'm not sure how you could cover up the ones on your knuckles.