Personally, I try to stick to a non-meat diet as I think the production of meat is a waste of resources. I agree with other posters - people that eat meat don't need to eat so much - quality is better than quantity.
When I was young, it was a treat to have a chicken at Christmas. Chicken is so cheap now that it's not valued at all. In a documentary about food waste I saw a woman slice off the breast meat and throw the rest of the chicken away. To produce chicken (or any other meat) so cheaply animals are intensively farmed and then pumped full of hormones, antibiotics and goodness knows what else.
I watched a programme on TV a year or so ago where the reporter flew over one of those mega farms in the USA. He said, even from the height he was flying at, he could smell the stench from the farm. In the UK we don't have the wide open spaces of places like Australia and the USA. Are people living nearby going to be subjected to this? My friend used to live near a very small pig farm - and it absolutely stank. Also, presumably, the vast amount of animal waste will drain into the soil and into the rivers.
This surely isn't progress.