There's no reason the club can't grow to a self-financing position but there needs to be a change in some key areas. The club has always been badly run, ever since I started watching them in 1994. They need a marketing budget, a competitive team, a competent management team, and an identity of their own.
At various times they've had some of those, but never all of them at the same time. Get that sorted and crowds and sponsors would rise enough to make the club sustainable. It's not actually rocket science, but a lot of the money David Hughes has put into the club has been completely wasted because the infrastructure has never been right.
The big plus for the club at the moment is that number of amateur clubs and schools playing RL in and around London is higher than ever. And the development programmes (only really in place for five plus years, are really kicking in. For example, last year the England Academy team played France and both halves were Londoners.
It's a long road, but it's doable with some sensible planning.