I understand your point, especially when you compare it to the situation of men speaking out after women are murdered by violent men.
There’s two things that I wanted to mention after reading your post.
When you write that you ‘doubt that [Muslims] care what us Westerners think’, it’s really important to remember that Muslims living in the West (e.g. Europe, the US and Canada, Australia and Canada) are part of this group of ‘Westerners’. They are just as ‘Western’ as people who are not Muslim; they are ‘Western’ and also Muslim.
There is a very small minority of people living in Western countries who call themselves Muslims but they are not Muslims at all. They believe in ISIS and Al-Qaeda ideology and they are against Muslim values and the values of democracy, multiculturalism and freedom of belief that is key to Western societies.
Also, the other point I wanted to make is, whilst Muslims could speak out about this, I’m not sure it makes sense for them to. First of all, organisations like ISIS do not have ‘Muslim’ values or beliefs in any shape or form. They are barbaric terrorist groups who survive by recruiting and radicalising vulnerable people from all walks of life and by creating an environment of terror, fear and destruction.
Also, Muslims are already the target of hatred, violence and discrimination in many countries around the world - partly because of more long-standing hatred and bias against them for a variety of unfounded reasons, and partly because of the fact that terrorist organisations call themselves ‘Muslim’. Why should we place another burden on them by expecting them to speak out about acts supposedly committed in their religion by a group that is not at all Muslim?
I think, actually, that it is the job of national governments to speak out against ISIS and Al Qaeda.
The British government, for example does speak out about them. They don’t always do it well, sensitively or effectively, but they do. It is the job of governments - and actually of everyone in society e.g. families, teachers, police, healthcare workers, youth workers - to stop people from turning to organisations such as ISIS and becoming ‘hardcore jihadists’, as you put it.
In somewhere like Russia, for instance, Putin might speak out against terrorists, as he has done after Friday’s attack. However, the problem is that Russian society under his rule is generally unstable, unhappy and disillusioned, due to his weak and egotistical governance and complete authoritarianism. Russian society under his rule has so many ‘push’ factors towards these sorts of terrorist organisations - e.g. poverty, lack of job prospects, racism, Islamophobia, poor living standards, poor life expectancy, lack of social and health care support, a relentles and bloodthirsty focus on the war with Ukraine - that this is one of the reasons why terrorist organisations are taking advantage of Russia and other countries around it as a source of recruitment.
You make an interesting point about why ISIS members aren’t shunned by their communities when they return to their home countries after attending ISIS training camps. I’ve never read any articles that mention what happens to people who come back home after attending ISIS training camps, so I don’t know the answer to this.
For situations where someone has been radicalised by a terrorist organisation such as ISIS and then committed a terrorist attack, I can only imagine that they plan the attack as secretly as possible, to avoid any sort of detection. Therefore, their families and people in their lives aren’t aware of what they are planning, and cannot therefore shun them.
Also, I know I’m saying something theoretical here, but I think ‘shunning’ someone in this scenario is the worst thing you can do. This is because it will push them further towards these terrorist organisations. They will feel more and more vulnerable and cut off from society, so they will have even more need to be accepted by a terrorist group who will radicalise them further.