Whats wrong with the frog analogy is that the the water in our pot is not heating slowly.
The analogy works if you consider how long ago the frog was put into the pot. The slow insidious infiltration designed to destroy our traditional culture has its roots in the Fabian society in the late 1800's and their heir Cultural Marxism int the early 1900's. 1913 was a particularly ominous year.