They have to, Since they lead lifestyles very different from the majority of people in other societies. If it is possible for them, Most prefer to limit their interactions with other communities to strictly professional and business-related concerns. This attitude extends not just to people, But even to the literature and philosophies of others.
In many western countries people migrated in the first instance to get away from the effects of Islam. In the early days those people happily joined the societies they entered. Later a substantial number of bullies and proselytizers came with them and made it difficult to shrug off Islam, by threatening behaviour. The example of these people creates anathema and all the "moderate" Muslims could no longer so easily escape, and they have to bear the opprobrium of regular citizens opposed to the baleful influences of Islam. This problem of isolation will go away when the enforcers are brought to heel. Thew best thing to do is to be kind to the Muslims in your communities, in recognition that many are stuck between a rock and a hard place.
I think isolation is a part of their religious culture and beliefs. There are many times when they have to be alone to pray, meditate, and other rituals. I meet a women of the muslim faith at a party. She had lock herself in a room by herself at a certain time to pray.
I believe that many Muslims do feel isolated in western and other cultures, mostly because the rest of the people do not understand their faith and link them erroneously with fundamentalists of their religion who may also be terrorists. There is a lot of fear and so like any group this one draws together for protection.
I think isolation amongst them would not only be a good idea,but its always been their style. I think if they keep to themselves for the time being, it would do well for them in the long run. I don't mean allow discrimination,but to just not protest in a violent way to stir the pot.
They do not seem to like outsiders of their people and of their religion. They even fight amongst themselves a lot, this shows that they are more likely to be isolationist. The Muslim countries of the world do not want to get involved with any of the other countries in the world.
No, I do not believe that isolation is a common issue among Muslims. Granted, I only have the small communities here in the United States to look at. However, as a community they appear to be very opening and welcoming toward outsiders. If I were to stereotype them, they are very friendly.