You can't just move out, even if the landlord isn't doing repairs - you are still liable for the rent :-( Not to mention the expense of moving - you have to find the deposit and a months rent up front, whilst still paying the rent on your old place.
I had a house where the oven didn't work for six months, and there was nothing we could do. Every time we rang the agent, they fobbed us off, so we would ring the council, who sent it through all their endless proceedures, got in touch with the landlord, who started repairs. The gas man was their friend and he basically dragged it out as much as he could, leaving weeks between visits, then finding that he had the wrong screw etc. Our entire gas supply got cut off twice, once with a foot of snow outside and a newborn in the house.
Then THEY evicted US. Two months notice, because they wanted to move their daughter in. They fixed the oven the day we moved out and we had to fight them through the DPS for our deposit back as they claimed random damage - luckily we had our check in and check out documents, and plenty of photographs.
I was seriously ill that month (I know they didn't know that) and so we had to find the normal rent, first months rent for the new house, deposit for the new house, agent fees for the new house AND van hire etc out of just XDHs wages.
I've had landlords letting themselves into my house, a smug git of an agent demanding a second inspection because my spare room had unpacked boxes in it (then practically patting me on the head when I had moved them), never ever got a deposit back before the DPS came in, always for utter bollocks reasons, refusal to stop the rain coming in, no warning that a house had a habit of flooding, moving the next tenants in before we had moved out (and were still paying rent) and just endless smug gittery in general.
I'm not going to risk getting a cat here, but I can see why a lot of tenants are very jaded.