I'd say it certainly is. Question is who's gonna help you if this happens? Would it be Visa or Coinbase? We can assume Coinbase isn't going to insure you for this type of loss. I don't know if Visa can do much either.
Cryptsy as trying to push its own Bitcoin debit cards onto its customers before it closed. It said they were the lowest fee cards available. Who would help you if your Cryptsy card got skimmed immediately before it closed? Visa would probably pass the buck to Cryptsy, and Cryptsy support probably stopped responding to questions after the closure.
I would check who's responsible for paying back skimmed funds before signing up for a card, and also check how reliable the company providing the cards is.