I don't think TA should be used to predict what prices will do, its a business planning tool so it is really for predicting what the trader will do. Nor should TA be burdened with having to identify the causes for why price did this or that: charts don't make prices move, they just display the movement.
But just because you can't (or shouldn't) use a screwdriver to hammer in a nail doesn't make it a useless tool.
Knowing that it was the Brexit result that caused the GBP price moves that followed did not affect how I traded them. Not knowing would have had no impact either.
Lots of traders burned their fingers trying to employ technical setups for trading on Pound when the information hit the market about UK referendum outcome. It all comes to results measured in profit and if TA have tools to keep event risk under control then it's great. But I couldn't actually find any tools for that.