The reason I prefer starting at 0 is due to a computer science background and also, I think it helps to start at 0 because there are certain reasons that demand it (in particular, combinatorics) and I think having exposure to starting at 0 is 'healthier' in the long run?
Teaching both starting at 0 or 1 is probably cause for confusion for a lot of students and they usually do not have the discernment to decide which to start at.
Any advice on the issue?