London is one of the world's top cities. That presents some substantial upsides, in terms of things like night-life, art, business activity, employment, diversity of the population, and, least tangible but most important, the general vibe of frenetic activity and constant renewal and change that a place like this has.
It also presents substantial downsides, in terms of things like cost of living, noise, pollution, transport congestion, and of course, the general vibe of frenetic activity and constant stress and change.
If you choose to move away from London, fine, go forth and be happy in New Whatevershire in the county of Who Cares... but don't write epic rants about how London's no longer to your taste and therefore it's somehow London's fault.
This irks me even more than anti-gentrification obsessives, who seem to believe that because a family has lived somewhere for a couple generations they should be somehow insulated from the consequences of rapid change and economic growth impacting a whole country.
Life is change. Change impacts everything, including your environment. If a place changes in such a way that you don't like it anymore, you're free to move somewhere else. Do so, and even write a blog post explaining why you moved, if you feel so inclined, but please bottle up the "my viewpoint is the only important viewpoint, and all change I don't like is bad" crap and keep it to yourself.