Earls Court is a very old out dated arena. The need for a large capacity arena in London is served by The o2. Yes through the years it has featured some amazing gigs but fewer and fewer bands are using it. Both Wembley Arena and The o2 suit the purpose of live shows better. As an exhibition venue it seems to have fallen out of favour too, with Olypia just up the road providing a wider range of halls and settings. Earls Court 2 is no better than an Aircraft hanger. The site, in central London, is worth more than the buildings and could be put to better use.
A number of bands who have played Earls Court haven't enjoyed the experience, Queen included. RT was quite vocal about it!