This sounds perfectly legal and 110% fair:
Let's look at what everyone does:
Greeters:
Seats the guest
Usually takes their initial drink order and relays it to the server
Busboys:
Clears the table (sometimes even during the meals)
Sets that tables (at most restaurants)
At some restaurants provides the refills (especially for water)
At some locations brings the food out if the server is too busy.
Servers:
Takes the order
Puts in with the kitchen
Provides refills (when not done by the busboys)
Brings the food out (when not done by the busboys, etc.)
Now each of these people deserve tips accordingly, it would be too much for the guest to figure out how to divide it out, as there may be other things going on behind the scenes that are being done, such as the server knows an order is wrong and is getting the chef to fix it, etc. that the guest never knows about.
In addition, including the tip in the check ensures that it is taxed appropriately, something that rarely happens with tips when left in cash (yes, I know there are those who are honest abut it, but a lot aren't), yes I think we spend too much in taxes as it is, but I do think everyone should be obliged to pay their fair share, if someone that is making just as much as I do has to pay 50% less taxes because their tips are in cash, then that isn't fair.
Just my two cents on the matter, I truly think that even cash tips should all be collected and included in the pay check. Although, if I were running a restaurant, I would simply pay my servers a good wage (I would try to figure out what good servers at comparable restaurants make per hour, after tips and pay a little above that and not allow the customers to leave tips, explaining that they are not needed here, if they want to let the server know they did a good job, either tell them or better still leave a little survey for them (the latter part would work for a bad job as well). My bet is by doing that and having really good food at reasonable prices, I would make a killing and always be busy, I don't think people truly like the idea of leaving tips and think that if just one restaurant stepped out of the box, that others would see it works and follow suit.