I have used and still have the stainless milk tubes. It is not draconian, and does not cause mastitis if used and cleaned properly. It actually slides into the teat and milk canal more smoothly, the offset holes on the sides will actually let larger chunks of mastitis to pass through... Not any worse than the individually packaged plastic ones that are not supposed to be reused; so they are more "sanitary"... Losing a quarter on a beef cow is just as bad as losing it on a dairy cow. They will produce more milk in the other 3 quarters, but not as much as they would produce with all 4 quarters. Dairies milk 3 teat cows all the time and have several on farms I test that are making an average 75-80 lbs a day right along.
If there are pressure problems... with the longer hoses, it is easy enough to just up the vacuum a smidgeon... the current thoughts are that it needs to be just under 13... most individual milkers (bucket milkers) are actually that high or higher. Too high a vacuum pressure will cause as many mastitis problems as too low, and too high will damage the teat ends so that bacteria is more likely to get up the teat. On the newer variable speed vacuum pumps, they run around 12.8....Too long a vacuum will more often just cause the milker to fall off, and not get milked out, so both directions can cause problems.
There is no big problem cleaning out the milk hose if it is done immediately after milking. Using a COOL water rinse first so the milk fat does not "set up" in the hose... then running a wash solution and then an acid solution to counter act the chlorine wash...
Cows can kick off any claw and I know of cows that will purposely put their foot directly on the hose to cut off the vacuum so it falls off, or just to pull it off.
Milking by hand in a bucket, a cow can step in the bucket and ruin the quality (great for pig feeding) or can kick the bucket over. There is NO FOOL PROOF way to milk a cow for pristine milk.... some cow will figure out a way to mess it up... The ones that are chronic PAINS get shipped.
Carousel parlors, which you call robotic milkers, are made in various sizes. I tested in a 72 carousel, and it has nothing to do with the feeling of being in a herd... it is the sensation of the movement that the cows enjoy... and there are cows that will stay on for more than one trip around, one of our other testers does a 50 cow carousel and he says they work on the outside, instead of the inside like we did.... there were 5 of us doing the testing in the 72 stall one, as it goes much faster than you would think. 2900 cows in about 8 hours... so over 350 an hour in a normal milking. There are some that are totally robotic, most here have people that do prep and attaching milking machine claws.
What we call robotic parlors around here, are individual stalls the cows walk into, their neck monitor or in their ear, and sometimes just as an ankle "bracelet"...registers the cow... tells how much feed she gets, doors close and she gets sprayed with a sanitizing solution, a brush type thing on an arm will clean them off and dry them, a laser is used to pinpoint the end of the teat to attach the inflation to each teat. The electronic computer can be programmed for 3 quarter cows, and every other type of info you can imagine. One robot will handle about 60 cows on the farms that have them around here...There are quite a few robot farms around here now because getting help has become a problem and the cows can be milked whenever they want. Most are programmed to allow for 6 milkings and feeding... a cow can go in more often but will not get fed or milked. Cows that do not like to go in will show up on a daily list for the farmer to go out in the barn and "find" and make them go in to be milked...A HUMAN still has to be an overseer, but it does not require you to be there twice a day at the same time every day.
Robots for these operations are about $200-250,000 EACH... monthly maintenance is around $1000 a machine... they require alot of time and work that a person milking does not. It is trading off of jobs. They are not a perfect solution.