I think if you're going to call people guest stars, they should be stars.
Semantic point, but since you're being just as semantic:
On the '80s show, the verbiage was "Today's special guests are..." or "Our special guests this week...". Don't remember the word "stars" ever being used.
If they're not anyone who I recognize or who projects a fun and likable personality, I don't care.
Okay, but what I get out of this statement is "If I recognize them, it's okay if they're a dud," which comes off incredibly shallow, or "If I don't recognize them, if they're fun and likable, I will enjoy watching them," which is a fine candidate for the Captain Obvious Memorial Trophy.
Neither statement convinces me of the validity of your argument.