They'll be somewhere between fixing things and making it better to breaking things and creating new problems that eventually need to be undone and re-solved, pushing the quality down and deadlines back.
People tending towards the second group are a waste of time and money. As a hiring manager, to be completely brutal, unless they can demonstrate they are in or have high potential to be near the first group, I simply do not care.
The contribution value of people in the second group is not zero, it's actually negative. Their bad decisions and buggy creations decrease the quality of the product. It's like putting an saboteur on the payroll and then handing them important responsibilities. The team likely becomes friends with them (friendships at work happen about 10 times for every 1 enemy) and this makes reversing the mistake even harder because after all, we are social creatures at heart.
What's worse, after the inevitable breakup, I then have to re-allocate my quality assets away from pushing the product forward to cleaning up the mess someone just left and things stop getting done in the meantime.