This isn't true. You tip for their service not sexual attraction.
It's hard to calculate the service they provide. Wouldn't you pay more for a pleasant drive than for an unpleasant one?
Besides these points, I think it is a stretch to say tipping is immoral.
Or you think you do: http://scholarship.sha.cornell.edu/cgi/viewcontent.cgi?artic...
"This study found that attractive waitresses earned larger sales-adjusted tips than did less attractive waitresses. Attractiveness had no effect on the tips of waiters."
If this was just based on (an even) salary, wouldn't it be better for everyone?
Which has a more attractive staff? Which do you suppose makes more in tips? (Or would in salary if straight salaried?)
I believe that in a straight salary system that more attractive people would be well served (no pun intended) to seek jobs at higher-end restaurants; I believe that's already happened to some extent. One table turn could tip $100 or more at a high-end place today. That will be partially shared with the multiple staff serving the table, but it's still going to be a very strong hourly rate.
Demand is on customer side, not on service company or place. If someone wants to be surrounded by attractive service and is ready to pay for it (not rejecting averages, of course), is he completely wrong?
Yes it is true. You may _think_ you do not tip for attraction, but in that case you either think wrong or do not represent a typical person.
https://psmag.com/attractive-servers-get-bigger-tips-2c7d89d...
http://www.businessinsider.com/the-startling-truth-about-tip...
I use Lyft when I have the choice now, but the tipping makes me uncomfortable. Tipping is why taxis drive past people of the wrong skin color. Tipping is why the most important thing in restaurant service is to be sexually attractive to your customers. Lyft does not entirely have the moral high ground, because it supports tipping.
Just pay your employees the money they earned and charge me the correct amount for it.