I guess it depends on the place. But the arguments for not including seem futile, when
- we use 0 to even write the other natural numbers
- we define almost all of our algebraic objects (groups, rings/fields, modules/vector spaces, algebras) to include 0
- we don't do modular arithmetic with {1,...,n} that would be crazy
Of course 0 vs no 0 only matters if you actually do arithmetic with it. If you only index you could just as well start with 5.
(The only reasons I can think of to start at 1 is that 1 is the 1-st element then and the sequence (1/n) is defined for all natural n)