Using a hosepipe during a ban is selfish. The people saying they would be justified in doing it because of failings of the water companies are kidding themselves, trying to persuade themselves that their selfishness is not, in fact, selfishness.
As humans, we survive by cooperating. People grow food and provide healthcare for each other. They also provide piped clean water into our homes on a mass scale. If the system broke down tomorrow, a lot of us would die. Only those who managed to scrabble together a subsistence farm next to a clean water source would survive.
Our water doesn’t appear by magic. It takes a lot of work by a lot of people. I suspect most of those people are doing their best although no doubt there are failings in the system and, as with pretty much any big system, things could be improved. Maybe there are also selfish people creaming off more than their fair share of profit while not doing their utmost to make the system as good as it can be, I don’t know.
But tit-for-tat selfishness does not cancel out the original selfishness. It makes things worse. It makes you just as bad as the fat cats.
It means there is less water for other customers who have done nothing wrong.
Imagine if everybody did it and we actually ran out of water. I hope at least then you would feel guilty.
The hosepipe ban and the systemic failings are two separate issues. If you feel so strongly about the systemic failings, get involved, help improve the system. Don’t sit at home “protesting” by having a lovely time with your paddling pool and your lush lawn.