A major assumption is that if we were to have a democracy in a majority Muslim country, that country will have to implement Islam because the people would demand it – and the Muslim people would never go against the will of Allah, would they? (note sarcasm).
Apart from the usual major fallacies of democracy e.g. non-representation, public unable to conceive of wider picture, hypocrisy of leaders and control by the wealthy – to name but a few; how would a ‘islamic’ democracy deliver morality and Islamic rights, when it is based upon self-interest?
Democracy works based upon self-interested people banding together and seeking to vote in someone who will represent those interests. Such a system is prone to factionalism, infighting, discontent on minorities and a general self-centred attitude to approaching politics in society. It matters not how good your morals are, because secularism WILL separate your morals from any real possibility of feasible practical implementation. That why people say, if you want to have a clean conscious, you don’t go into politics. Take Indonesia for example, there already exists factionalism and infighting in it – and that is because of democracy. Some minorities are so tired of having their interests ignored by the majority, they want to separate themselves so that they become a majority in their own country!
And finally, if we are actually concerned about establishing the will of God, in regards to politics, why not just establish the sharia law directly and not gamble on the hope that the self-interested groups in the population will do the right thing and not just the most convenient thing (which they usually tend to do, if left to themselves)?
In the end, the Western world is developed because they came to an agreement that it is in the common (self) interest to use technology to make life more enjoyable (and convenient). As Muslims, if we want to get as developed (if not more), we should rediscover our original motivation that caused us to develop – the worship of Allah (swt) and the never ending striving for the absolute perfection of His (swt) pleasure.