When I was a kid, I'd sub for whoever needed an extra hand that day or that week. I got to work for a LOT of companies that way. You don't do that if you can't get along with people. And the way I got jobs was, trunkslammers would call other trunkslammers, asking if they knew anyone looking for work who already knew how to punch down a patch panel and spoke at least a little English and wouldn't OD at lunchtime.
Lots of times, a customer would get ticked off at a company and ask another company to take over the service, or the monitoring of the burglar alarm or fire alarm, or whatever. Then there'd be a delicate dance with the other company- you've got to either get them to give you their administration password or replace the equipment. Keeping the equipment in place and just rehabbing it and reprogramming it to use meant significant savings. You also want to know why the customer is leaving the other guy and looking for a new company. Everyone has that one job where everything went wrong- drilled into a pipe, couldn't find a short, forgot to wire a window, insulted the guy's wife, whatever, until the customer's patience ran out and they throw you off the site. And everyone has that lunatic customer who is all sweetness and light until the first bill comes due, and then they lose your number, or who is always on the phone with insane questions, who leaves long rambling paranoid messages on your answering machine, and always wants changes done. So you gotta find out, did the customer fire the company, or or did the company fire the customer?
Lots of times, I'd say, yeah, my admin code is 1234, and by the way, this lady was really mad that the aliens who rearrange her pantry isn't showing up on the cameras, or that guy still owes me $600 from last year and his checks are made of rubber.
And you can only do that if you have the other guy's beeper number or BBM code, or you know where he hangs out so you can meet personally. The trunkslammer community tends to stick together in Brooklyn, where I learned this business.
Of course, there's people and companies you dislike on a professional level- you only get to screw people over once, and if you screw someone over, all his buddies will hate you, too- and there's people who you tend to dislike on a personal level, like that jerk who I hate because of what a big fat stupid jerk he is (you know the one). But it's not like that's common.