Generally speaking, yes. Because if you "pop" up into an upright position, you have lost a lot of power and momentum you could have used from the spring in your legs.
It might be different if you were throwing uphill, or trying to slam-dunk a baseball.
Keep this in mind: ideally, you would like the ball to move on a downward path from your hand to second base (no arc). With that as the ideal, you need to get as much leverage and momentum BEHIND (not under) the ball as possible. You also need to "power" the ball to 2B as quickly as possible. So the plan is to get backward-forward motion, and the way to do that is by staying low. By staying low, you are taking advantage of the driving force of your legs.
It's not unlike a football offensive lineman hitting a sled (or defensive tackle). The lineman is taught to stay low and use his lower body strength to drive from a 3-point stance, forward and into the sled/defensive lineman. If he "pops up", he loses much of his leg power and is easily manhandled, as he is relying almost exclusively on upper-body strength.