That reasoning is just a lazy excuse for oppressing people with viscous, ignorant stereotypes. The generalizations are not only unnecessary, they are wrong and the foundation of much of the evil humanity does. People are individuals, with their own behaviors, beliefs, actions, etc. and that is what they are responsible for; there are good and bad in every house, on every block, in every town in the world. To imagine that you have any knowledge about people spread across continents is absurd, and to even claim it demonstrates an embrace of ignorance. Again, it is the parent comment's behavior that is the problem.
> If enough people within my culture agree those aspects are a great danger then collectively we can outlaw them or otherwise oppose them.
No, if you are in a Western country you cannot outlaw humans based on their supposed "culture". It's illegal in most countries, it is antithetical to freedom and other Western values, and we've been there before. Shall we round up the Jews next? Black-skinned people?
> I am a member of a culture making a value judgement about aspects of another culture
You're not a member of my culture, based on what you say, and the evidence I have is far stronger than the color of your skin or the country where you were born. Can I make value judgements about and ban you? (No.)
IMHO, it is the good and peaceful against the hateful, no matter where they are born.
> If Islam were to become the major culture in the West ... Is that something you'd be ok with?
Absolutely. I want people to follow the religion of their choosing (or none at all, if they prefer); I'm happy for them if they can do that; I will defend their right to do so. That is a fundamental value of Western culture; the freedom of religion is one of the fundamental freedoms in all Western nations.
I wish my country would open its door and encourage Muslims to come and live in freedom here, where they will be loved as neighbors, respected as full citizens, and can worship as they wish without fear.