#2 NXT proves that less is more
The first temptation is to think that more TV time can improve the quality of the product, as superstars will have more chances to show what they are capable of. But NXT programming shows that this is not necessarily true.
NXT's weekly show only runs for an hour, and on top of their Takeover shows, their airtime does not come close to WWE's main shows. Yet NXT's product is compelling for its in-ring action, as well as the stories they are able to tell, there is no need for them to extend their weekly running times in order to improve their shows.
Overexposure is a detriment for creating stars and adding an extra hour will make this worse for SmackDown. NXT has benefited from a shorter show with fewer matches, but crucially these become more meaningful because they are so scarce.
Having a longer show means more meaningless matches which will dilute the overall product. More promos and filler matches are more likely to damage a stars progression.