I don't see what the issue with flying out own flag behind speeches from our own Pm or Ministers is. I don't think it is a necessity to be "patriotic", but I think if you have an issue with it, I question your patriotism - I don't see the issue with it. I like it myself.
I went to the US om business a few years ago at a government agency and they had US flags in all of their rooms, which I personally like. I think their random flags all over their streets is over the top, but on and in governmental buildings why not? Especially if you have such a great and iconic flag as we do. What I do find cringeworthy is some of the big European leaders having flags behind them when they speak - I have no issues with them having the French or Irish tricolore or German flag behind them, but cringe to see it combined with the EU flag.