I've noticed something on multiple different stack sites that confuses me. For some reason, the reputation requirements for certain privileges are different.
For example, you need 50 reputation be able to comment on Stack Overflow questions, but you only need 5 on Meta Stack Exchange.
Another example, you need 1500 reputation on Stack Overflow, 500 on Meta Stack Exchange, and 1000 on Math Stack Exchange for the same privilege; create tags.
Why is that?