In college I spent a couple summers doing repair work in the shop of a family friend. I got stuck with a boondoggle repair and when it got into day 2 that I was still working on it, and the manager got pissed off and tried to take over for half an hour before he figured out why it was taking me so long. Then we had a shocking conversation about the fact that while he was paying me $x/hr, I needed to be booking at least $10x/hr in repairs, so I needed to work faster. It seemed so unfair to me until I spent a lot more time working in small companies.

The repairs were a profit center, and the labor I was billing was keeping the utilities turned on, buying replacement tools, consumables, paying for my lunch break, covering rework, a hedge against me injuring myself, paying for the shop van I used to run inventory between stores, paying taxes, business licenses, my manager's salary, the owner's salary, paying for Bob to wander over and consult on a repair I wasn't sure about, paying the interest payments on the loans, and covering the loss leaders that got us repeat customers who needed repairs in the first place. Things like trade-ins and entry level equipment.

At your programming job, every manager above you in the chain, every support team that you use to get your work done are all being paid out of the money billed for you. Yes you may be writing $1M in software a year, but the company wouldn't exist and you wouldn't have any sales without those other people, so all of that overhead gets subtracted from your value. Ironically and possibly painfully, a company can exist for months without a single programmer, but it can't exist long without a management chain.