If the shunning of religion by the West was because of lifestyle and economics alone then I would be inclined to agree with you but I think you left out one prime reason why so many people are turning their backs in the West; evidence.

Science is accelerating at such a rate now that it is totally imploding all the myths and falsehoods that religion used to be used to fill in the gaps of.
The main sneer at science is that it 'does not have all the answers' but it is proving time and time again that it is turning the pile of things we don't know into a pile of things that we can explain.

Science in the West is eroding the cast-iron certainty of believing in the words written in a book thousands of years ago by scholars who had little or no view of the world, zero awareness of DNA and mental health, little morality on human rights and slavery and racism, the list goes on.
In a 'free-thinking' society, facts matter. They cannot be ignored if they make sense.

Against this is the attrition of Religion, not just Islam but they are the highlighted ones for being the most hard-line in a time of wavering belief.
They are a mass of humans who are un-reasoned with, a bunch who would say that even if you gave them ALL the scientific facts for the proof that there is no God (evidence which is not yet available) then they would STILL believe anyway.
That is at odds with the Western view. While many people would keep their faith in the above case, they would be wavered by science and not just follow blindly anymore.

Science is advancing the world, and is a beautiful and wonderful thing. Who doesn't get excited about finding out how we truly got here, how we truly exist?
The thing is, that truth erodes the foundation of religion, and the West gets attacked for advancing our knowledge by being accused of....women wearing skimpy clothes, adultery, loosening of morals, lack of self control.

That is a desperate argument though.
While they have a point that 'if that is advancement, then we want no part of it', they lump science in with that evil-living package and also fail to realise that many people in the WEST want a change in THEIR OWN societies.
Islam could understand that not all people in the West love the images stuffed into our eyeballs and the lack of clothes on our women or the faltering morals. The West just does not think Islam is the solution to curing that social ill, and Islam does.

Keeping your people in the dark and not advancing their minds is a fear tactic, and the same tactic used by the US against Islam; 'look, these people are trying to take your freedom of living how you want to live'.

The facts just don't point to there being a grand designer anymore, one person who made the world. It is not a sustainable story anymore. Evolution is a theory, but not a 'well this may be the way things happened' "theory", but a 'theory' in the other use of the word; "a scientific proven fact, a theory of factual explanation".

The West is doing itself no favours by slowly revealing this wonderful truth through Science....then having a broken, immoral society. Because then the facts get ignored and lost and lumped in as part of a blanket campaign against a debauched lifestyle that is easy for the outsider to say 'yuck, we don't want to live like YOU. Yes they may have science but look how they LIVE'.

Everyone wants to have the answers to life.
But it is one thing saying 'we haven't found out yet' and another thing keeping alive a story just to say that you do.