I think it comes down to their policy of adjusting to provide the same quality of life, which I disagree with for remote companies. Their London salaries are fine, but one of the main reasons for me working remotely would be to increase my quality of life by living more remotely but still earning a London-like salary. Otherwise you've moved away from many conveniences, will likely have to pay much more for travel, but will still have to live with the quality of housing you could afford in the city.