While I absolutely hate this, I will note the suggested tip is lower than what is usually asked for.
It would be better to have two tip lines on the receipt; one for front staff, one for back staff.
Edit: I'm just going to put a PS here as people seem to me missing my point (and the first 5 words). I'm not recommending this practice. I was suggesting an improvement on a shitty thing. My initial point is that: I'm honestly surprised that they DIDN'T have the audacity to recommend no less than a 15% tip.
The suggested tip may be less than what's normally suggested, but even the 'minimum' 8% tip means it adds up to a total of 26%, which is way more than my own usual 20%.