Not so. You have it backwards.

Adopting the best of all cultures to create a new syncretic one IS the melting pot, with people from various races, cultures and ethnicities mixing and interacting and sharing their cultures, and that is what most people want and thought they would get with "multiculturalism".

What almost no one wanted or anticipated was that what it really meant was the creation of those cultural silos with little  mixing or interaction, i.e. the " sticking with our own kid".