I find myself using Cmd-Period now and again. Not often (with experience you learn how to avoid most of the things that would make you need the command). But it is Good that it is there.
Note that Cmd-Period does not cause a Stack Overflow. It only interrupts the scheduler. If you're getting an Alert saying "Stack Overflow," then you've got a stack overflow and you really should be saying Thank You to kind Mr. Zicarelli for putting some safety checks into the Max scheduler. In the old days Stack Overflow used to reliably crash Max (and sometimes even the OS).