assalmau Alaykum,
I think it is bit over the top, because the extremists are so very very few. It is not as if we give talks in our Masajid to make people stop extremism. (because we dont need to!!) Sure we critisise extremists, but it is not as if we have this huge problem in our midst. This is the image the enemies of Islam want to give in order to skate away from the core issues.
To see people getting up and walking out of a talk about peace, this is not what a typical Muslim gathering is like. -- It could give picture that Muslims have a lot of problems in this regard.
Although, it is good that some people will realise that extremism is not from Islam and that we do not condone terrorism
What people dont know is the extremist groups are funded by the same governments that later wage wars against them and that needs to be stopped!! - Do some research guys. Various individuals have had contact or been part of government funded secret organisations. For example, Alexander Litvinenko the Russia spy who was murdered recently (and who became Muslim before dying alhamdulillah) talked about how the Russians had given some training to the London bombers and even to the extremists in Iraq such as Zarqawi.
Factually proven incidents of governments giving aid to extremists or war criminals includes the US funding and training of Guatemalan war criminals in methods of torture and terror, also they sponsored AlQaeda and the Taliban as well as funding various groups in Lebanon. Israel was sponsoring Hamas (for 20 years!) in order to counter the PLO, they also funded and aided Christian militia groups responsible for murdering thousands of Palestinian refugees in Lebanon.
So, please look at things from different perspectives. Muslims are not the ones who are to blame. - Terrorism, more specifically STATE terrorism is closer to home than you think.
wasalam