Dont judge them to quickly see how things are in the long run, they are engaged in politics in difficult circumstances - sometimes this causes for compromises that don't look good to devout Muslims, but which cause good in the long run.
For a parallel situation look at the Adalet ve Kalkınma Partisi in Turkey. It too is basically seeking to serve the interests of Islam but it has only done this through massive compromise and it is doing very good work by gently undoing the Secular Fundamentalist machine in Turkey.
The Ikhwan has moderated its Islam far less than the AKP, but that which it has done has been for the same reasons and it is starting to bear fruits. Wait and see what the Arab spring develops into. It may very well see a new flowering of Islam in the political sphere.
For someone who doesn't know anything about the Ikhwan the following links may be informative...
About Imam Hassan Al Banna Shaheed (ra)
Letter to a Muslim Student
A Great Sunni Sheikh who used to be the head of the Muslim Brotherhood in Syria
Wikipedia's informative (but typically hostile) page on the Muslim Brotherhood. It is good for someone who is unaware to know that the Ikhwan is active in nearly every Muslim country (Indo-Pak excluded) working patiently for the restoration of Islam to the sphere of government. This Wikipedia article can give them some idea of this work.
PS. many of Syed Qutb's (ra) ideas were denounced by the leadership of the Ikhwan in the past, so don't imagine that it is his ideology that governs the movement - it is (and has always been) the ideology of Imam Hassan al Banna (ra) that guides the Muslim Brotherhood.
Also Muslim Brotherhood includes both Salafis, Modernists and traditional Muslims, they are far from an Arab mirror of Jamaati Islami. Sheikh Yusuf Qaradawi may be an influential scholar with the movement as a whole, but there are people associated to it who have very different views on fiqh from his.