Bryce Harper hit 154 groundballs last year. Let's say, somewhat unfavorably, that an average infielder has a fielding percentage of .970 and they are equally likely to make errors on "routine" groundballs as other plays (untrue). So we can expect about 5 errors on Bryce Harper groundballs last year.
In the most unfavorable scenario - making an out failing to hustle while leading off, instead of getting to first base - he costs the team .6 runs per failed hustle. So 3 runs per year.
Of course, most players including Bryce would be hustling on more difficult plays anyways, so I'd say its more like a run a year if you never ran out two hoppers to second base.
As Mark McGwire once said (paraphrasing), y'all wanna see me run out some routine groundballs? Or y'all wanna see me sock a few dingers?!?