Interesting take, and only mildly applicable with your ATP stats.
Even Federer often hit's a slight bent arm forehand.
How do you explain all those super bent arm forehands of the WTA players, those girl's getting more coaching than anyone in tennis.
You might be saying a more straight arm groundies is a more advanced level of groundie, of which I cannot deny.
But, if the ball has already bounced, it's much too late to move any feet or legs to compensate for inexact spacing.