That's entirely subjective, though, and frankly, unless they're actually wasting water/leaving taps running, etc, or actively defying things like hosepipe bans, then I don't really see it. The issue is a lack of infrastructure, not a lack of water in an island nation with plenty of rainfall.
Why is maintaining a garden madness in a warming world? Much better than paving or tarmacking over it or indeed putting down fake grass.
As for flushing "drinking water" down the toilet, why is that bonkers? It's not like people have two different water supplies, the water supplied to people's homes isn't only for drinking, it's for washing and indeed flushing toilets - if you think flushing toilets is wasting water, then I'd certainly disagree if that's included in what you'd deem to be irresponsible behaviours.
What are people supposed to do instead - go full hippie and get a composting toilet? Or do the eco-warrior stuff like not flushing after peeing/flushing for no2s only or putting a brick in the cistern to reduce the flush? We shoudn't need to live like that - it's completely ridiculous that succesive governments haven't allowed for basic infrastructure investment while the population has carried on increasing.