Because: a) comma has already defined meaning so it could be ambiguous - it would mean tuple (2,333) in python for example b) even if its not the case, its ea

Because: a) comma has already defined meaning so it could be ambiguous - it would mean tuple (2,333) in python for example b) even if its not the case, its easy to confuse it with floats, and you do not want apply local numerical conventions to code and discover one day that all your ints are floats because some setting was different c) you can write it as 2_333 in growing number of languages