Roger Scruton says that the problem with Islamists is that they take themselves too seriously:

Now of course it is wrong to give gratuitous offence to people of other faiths; it is right to respect people’s beliefs, when these beliefs pose no threat to civil order; and we should extend toward resident Muslims all the toleration and neighborly goodwill that we hope to receive from them. But recent events have caused people to wonder exactly where Muslims stand in such matters. Although Islam is derived from the same root as salaam, it does not mean peace but submission. And although the Koran tells us that there shall be no compulsion in matters of religion, it does not overflow with kindness toward those who refuse to submit to God’s will. The best they can hope for is to be protected by a treaty (dhimmah), and the privileges of the dhimmi are purchased by onerous taxation and humiliating rites of subservience. As for apostates, it remains as dangerous today as it was in the time of the prophet publicly to renounce the Muslim faith. Even if you cannot be compelled to adopt the faith, you can certainly be compelled to retain it. And the anger with which public Muslims greet any attempt to challenge, to ridicule or to marginalize their faith is every bit as ferocious as that which animated the murderer of Theo Van Gogh. Ordinary Christians, who suffer a daily diet of ridicule and skepticism, cannot help feeling that Muslims protest too much, and that the wounds, which they ostentatiously display to the world, are largely self-inflicted.

He also notes that for this reason, and others, “fascist” is not an unreasonable word with which to describe them.