I don't think 0-based was ever as common a practice as it is today, especially in the 60s. In the beginning there were two camps fighting which system was to be preferred and there were many more 1-based or agnostic languages (like the whole Pascal family). "Numerical Recipes" a pretty popular book for some time even came in two editions, a 0-based and a 1-based version. I think the victory of C had a big influence on 0-based winning.

Personally I find it very sad that the agnostic approach of Pascal did not prevail. Let the programmer decide what they think fits the situation best and let the compiler deal with the technicalities. This, and I also miss range types... for like 40 years now...