Without a controlled study that provides evidence that snakes who drink from disposable cups are spared a significant risk in comparison with those who drink from ceramic bowls, i will continue to think of people who use disposable as incredibly selfish, and will favor the less wasteful breeders.
Most larger breeders go disposable for business reasons they are paying someone or are logging their time when it comes to cleaning.
Now I can store 5000 disposable deli cups in the same foot print that I can 1000 non-disposable bowls then disposable is the way to go. Also if it takes an employee or me 30 seconds to 1 minute to clean and refill one non-disposable but I can toss and fill 30 deli cups in one minute then for the payroll overhead budget its cheaper for the business to go disposable that cost saving is then reflected in the price I have to charge for that animal. Which is better for my customer.

Now if you have the a small collection or the time hey go with crocks or dog bowls all my bigger animals have them but for baby's its much easier to use the deli cups based on the size tub I use instead of trying to find a bowl that will fit.