OK folks-
Lemme splain this to you.
There is no doubt that chickens PREFER to drink from a pool of standing water. This is provided by the conventional, trough, pan, vaccum waterer, cup, etc with standing water in it. In addition there to the chicken prefers to drink it at ground height, the natural location of water in their ancestoral environment.
Chickens get excited or are very interested in new things in their environment. That is one of the reasons the chickens run to the pool of water to drink.
Chickens have not figured out that they should not drink contaminated water. Yes - I know all about your Grandma's hens drinking horse pee and other such liquids but it is undeniably not as good for them as clean water. In the industry we go to exteme lengths to provide them with as pure water to drink as reasonably possible. If the water is contaminated in in the slightest bit we notice decreased interior egg quality, decreased hatchability and greater carcase rejection from interior (eviscerate) condition in meat birds.
At first the poultry industry resisted the use of nipple drinkers. They saw the same problems that many of you have observed and even more so because of the scale, scientific and statistical anaylasis available to them. But when the "bugs" that really matter were worked out the industry has adopted nipple drinkers almost totally and worldwide.
Grandparent generation, and even more ancesteral, commercial layer breeders (this includes all the white egg layers as well as the ISAs, Golden Comets, sex-linked brown egg layers you know) drink out of nipples. The last flock of grandparent Hy-line brown egg layer breeders that I heard the price on were about $27.00 per bird DAY OLD CHICK PRICE! Now just how much water deprivation do you suppose the owners of these birds would tolerate?
Parent generation broiler breeders (those are the parents of what you call cornish x) cost about $25 each (females, the males cost more) when they go to the breeder house. They lay an egg that by rule of thumb is valued at $0.50 per egg. Depriving these birds of water would be foolish. Especially in hot climates. I can tell you because I have personally seen it that broiler breeders are watered with nipples in rather warm climates. How about Isreal and Egypt?? Let alone GA and AL
Then take the 9.2 Billion meat chickens raised in the US per year. They all drink out of nipples. Do you suppose that they are denied the most essential and cheapest nutrient available.
And. Almost all of you maintain greater water column heights on the nipples than commercial operations do thus delivering even more water to the bird.
What you perceive as your chickens "likes and dislikes" are not the most relevant factors in good animal husbandry. Just like your kids and chocolate, video games, tattoos and motorcycles.