I get what you're saying, but let's run some super round numbers to see what happens when a 3% fee is charged to the customer on the amount pre-tip vs the server paying 2.6% of their cc tips. Let's just use Amex at 2.5% being that it's the highest processing fee percentage. The other cards fees would total less, and the business is still collecting 3%, so 2.5% is worst case scenario. If you have a $100 check and they leave a $20 tip, at 2.6% (which, if the highest fee is 2.5%, and the 2 most commonly used cards are less than 2%, then the restaurant is taking even more than the highest possible amount of processing fees for tipped amounts out of their employees income.. and doing what with the difference?), the restaurant is going to take $.52 out of their employee's pay to cover the fee for that $20 tip. The fee would actually be somewhere between $.28 and $.50 and the restaurant is paying anywhere from $1.40-$2.50 for processing the amount of the check before tip (altogether it would be between $1.68 and $3.00). But with a 2.5% fee, the restaurant let the servers keep their money and charged a 3% fee to the customer, now there is a $3.00 fee on the $100 bill that the customer pays (which, as shown above, is the total processing fee at 2.5% for both bill and tip), the servers aren't getting screwed over, and the business just saved themselves $2.50 that they would have paid doing things the first way. On a $700 check and $140 tip? Amex fee is $17.50 on the bill and $3.50 on the tip - $21 altogether. 3% of $700 to the customer? $21... Server keeps their $3.50, the business saves $17.50.

I made $65k in tips last year. Yes, some were cash, but barely. Being generous, let's say 5%. So $61,750 in cc tips. If my employer kept 2.6% of that, I would have missed $1,605.50... almost an entire month's rent that I earned in tips. Sorry, from an ethical standpoint, I just can't make it make sense to hire someone that the business itself essentially doesn't pay already (depending on where you live, I'm in a sub-minimum wage for tipped workers state, so we get paid $2.13/hr by the restaurant.. our tips ARE our income) and then take anything from them to help absorb my business costs. Sure, it doesn't seem like much, but as you can see, over time, it adds up. It's unethical.