What I never understood is why our protagonists never tried simply overpowering the Personal Borg Shield (TM). Any time shields are fired upon in ST, the shields are weakened. Yet when the drones 'remodulate' their shields to adapt to phaser frequencies, our heroes give up. They never seem to have tried firing more in hopes to overpower the shield and penetrate it.
Well, if it takes 10 shots to overpower a drone's shield, and you're getting swarmed by an ever-increasing number of drones ready to corner you, then you look for a more efficient means of taking down the enemy.
As an aside, with the exception of Worf, I don't think there are any main Trek heroes who rely on beam-spam anyway.
Alternate nitpick: Why must drones move along so damn slowly, like zombies?
Drones can't think for themselves, are pale skinned, and have an almost primal urge to turn you into one of them. They're zombies alright
In-universe reason: no idea. You would think that with that many mechanical enhancements, a drone would be more like the Terminator than Robocop.