You can't blame Brown for the financial crisis but you can blame him for the position of the UK economy at the time. Here's what Ken Clarke had to say about Gordon Brown in 2005, well before the crash.
https://www.theguardian.com/politics/2005/apr/25/election2005.economy
Excessive borrowing? Public finances should have started running a surplus by this point? Surely not!
Our economy has recovered just fine. Not spectacularly but not terribly either. You can't credibly borrow to invest when you're already up to your eyeballs in debt and lenders are about to start charging you higher interest because you haven't been paying down your current debts. That's all down to Brown. About the only time when he ran a surplus was in his first couple of years as Chancellor, when he stuck to Ken Clarke's spending plans.
Also, the idea that Keynesianism is a formula for recovery just doesn't match what happens in the real world. You can cite the US economy in the 1930s but what about the UK economy at about the same time? The UK slashed government spending (Ramsay MacDonald was thrown out of the Labour Party for going along with this) and proceeded to recover much faster than the US. Now this is quite simplistic - I've seen people argue the real key to the 1930s recoveries was how quickly a country ditched the gold standard and the problems in the Eurozone show the difficulties economies have when they don't have a floating currency - but it shows that spend, spend, spend isn't the only ( mor even the best) answer. The French weren't fans of austerity so rejected it by electing Hollande in 2012 and their economy hasn't recovered as well as ours since then. The Japanese have tried a few times to give their economy a Keynesian boost since 1990. It hasn't worked, it's just left them with a vast national debt. So you can't claim that spending is the unquestioned route to recovery.
Even when it does work it comes at a cost. The 1970s (it's that decade again!) was when Keynesian economics finally left the U.K. in a financial mess and forced Jim Callaghan to go 'cap in hand' to the IMF. Callaghan then admitted "We used to think that you could spend your way out of a recession and increase employment by cutting taxes and boosting government spending. I tell you in all candour that that option no longer exists, and in so far as it ever did exist, it only worked on each occasion since the war by injecting a bigger dose of inflation into the economy, followed by a higher level of unemployment as the next step."
Gove on TV last night suggested the Tories will start campaigning more on the economy and I think that's a sensible move. Labour are claiming they can fund a massive spending spree just by taxing business and the top 5% of earners. It won't work - when France tried to tax the richest in society the rich just left the country. If/when people realise that increased tax on business is unlikely to raise as much money as predicted but is likely to mean lower wages and fewer jobs and that they will end up having to pay more tax themselves Corbyn's plans may not look as appealing.
