Your calculations are correct and do maximize profits. While squeezing every drop of profit out of the lane, the next logical step would be to hire part time drivers to run these or any lane for, let's say $15/hr.
Now, using your analogy, we can pay .55/mile for an 550 mile meet/turn or > $300 plus drop/hook pay+ benefits OR we can pay $15/hr or around $150... No insurance cost etc. You're welcome to do the math to figure the cost savings.
Again, using your analogy, it's fine with you and we should just understand that it's all about maximum profits, even though they'll loose some reliability, and integrity. So when these trailers don't make it on time and service suffers, will you be here defending the company's decision based on profitability, regardless of the ethics involved?
Where does the search for maximum profits end?