Because that increases complexity, and introduces new ways the installer can do something unexpected or fail. There's overhead to code; it has maintenance costs

Because that increases complexity, and introduces new ways the installer can do something unexpected or fail. There's overhead to code; it has maintenance costs. If half a dozen people in your town of 10,000 use bins for storing soup, but one year the council procures bins with holes in the bottom to keep rain from collecting in them (making them hard to move, and also providing stagnant water for mosquitoes, ie something that benefits nearly everyone)... ...what would be your opinion of a blitzkrieg of online and media criticism of the council for not considering the needs of soup binners...by people who do not store soup in their bins but are screeching about the needs of the people who do and they say will be affected by the change? And then someone on the council has said "alright, fine, look...I doubt there's that many of these people. I'll go talk to them, who are they?" and the screechers admit they don't actually know any soup binners, so the councilmember looks them up and goes to the house of every soup binner and either plug the holes in their bin for them, gives them proper soup pots, or prints out a list of soup pots they can find on amazon...or finds out that they say "well gosh I had a soup pot in the attic but I never got around to using it, I'll just switch. Thank you for the heads up that the new bins will have holes in the bottom."