It doesn't matter why. Your claim is false regardless of the reason.
elaborate.
The disease (or rather diseases) still exists in parts of the world. It's spread across Europe was was halted by a number of factors that aren't applicable to measles.
Yes, it does exist, like measles. Researchers still don't know enough about measles to eradicate it, either.
Utter hogwash!
Having a weak immune system is not the same as having an immunodeficiency disorder. Let's not equivocate here.
Unless you want to argue that all the 147,000 people that died from measles in 2013 all had an immunodeficiency disorders, your statement is false.
Oh, yes, I am willing to bet that all of them had improperly functioning immune systems at the time their measles crisis began. They were most likely malnourished in the extreme.
You want to find me a confirmed case of a healthy, disease-resistant immune system that was destroyed (to death) by a simple case of measles? Because you'd have to do that.
Find a person, one person who had been proven to have a healthy immune system before being killed by measles. Not young, not athletic, not pretty. Proof their immune system was fully sound, and was destroyed by measles, not antibiotics or other drugs.