At the end of the night, if they work 4 hours.  They will come out at least with 29 dollars that night.  If they do not like that pay, then they need to find a new job.  No one forces you to work in a tip based industry.  Its on the employees and its really not my problem.  I am not saying I do not tip, but at the same time, I dont feel bad if I dont leave a tip.  They are at least getting paid 7.25 an hour if they dont get any tips for that hour.
But back on topic, I will not tip anyone who is not in a tip based job.  In fact, a lot of employers forbid it.  Housekeepers are paid whatever they are paid.  They are not included on the $2.13 pay scale.  They get 7.25 an hour at the least.  Also, what is the difference between a 100 dollar steak and a 25 dollar steak to a waiter?  Nothing. It weighs the same if not less than the 25 dollar cut.  It doesnt effect their time any differently.  Why would I tip based on cost when a waiter at outback is probably busing their own tables, getting drinks, bringing food, plating food, etc when a waiter at a fine dining restaurant just brings the food and the check.  That is why i dont tip a percentage of the bill.
I went to a don pablos.  Nothing fancy or expensive.  I had one of the best waiters ever.  My bill was 45 dollars.  I tipped him 50 dollars because he made an ordinary night, into something special for my family and I.  I think from our table, he made over 400 dollars.  That is how I tip.  Dont do anything special, you get 5 to 10 dollars.  You suck, you get a penny.  Its as simple as that.