Ty Webb
Uh, maybe because that gives YOU a "heads-up" during your taxi-out or pattern work that someone is going to be entering the pattern in a few short minutes and NOW is the time to think about coordinating? Of course, this only works when you have your radio on and are communicating?
Second thought- forget about it. You have too much to learn and it's not my job to teach you.
Have a nice life. . . . . and thank god for TCAS. You do turn yuour transponder on, with all that juice you're saving by not announcing your position, aren't you?