But my point is - why should I have to pay taxes on business expenses reimbursements?

Think of it this way: Let's pretend you go on a business trip and spend $250 out of your own pocket to cover various expenses. When you return home, you submit an expense report and in turn, your company writes you a check for $250. In that scenario, you are not taxed on that reimbursement.

Conversely, in my scenario, I spend upwards of $6,000 every year fueling and maintaining my personal vehicle while using it for business. My company pays me less than that to partially compensate me for that use. However, in my case, that compensation shows up on my W-2 as income, meaning I am taxed on that compensation, further increasing the disparity between the compensation and my actual out of pocket outlay. In my mind, it is absolutely reasonable that people in my situation should be allowed to reduce their tax burden based on these types of expenses. Essentially, my "expense reimbursement" is simply an increase in salary, and my job-related expenses are not directly compensated.

Does that make sense?