No one has to assign compensation value to persons or positions, because a capitalistic economy does it for you. Cops and soldiers are tremendously valuable, but offer soldier or cop jobs at $100K salary per year and you will have more qualified candidates than you can handle. Advertise job openings for a neurosurgeon paying the same $100K and will have a tougher time filling the position. That's why the cop makes less and the surgeon makes more.
I can't repipe my own house, but I'm not paying someone $450/hr to do it when I can get many good plumbers for a fraction of that amount. When my business needs legal advice or services, I've paid that $450/hr found it to be very cost-effective. That doesn't mean the lawyer is a better person than the plumber, it just means he completed the education and experience that qualifies him to do that specific work more effectively than others.
Back to the tipping question, life would be simpler if people were paid a fair wage and tipping wasn't necessary. I would rather you tell me my hotel room costs $200 per night and let me pay it, rather than say its $160/night plus I have to give cash to every hotel worker I encounter, for a total of $195.
Tipping can show appreciation, but it also becomes a form of bribery for special treatment. Pay extra and you are treated well, pay the listed price or fee and you are treated less well because someone else tipped more.
I tip because society expects it in the country where I live. That doesn't make it logical or even correct.
Well said!