Because where will it end? Smokers are easy targets...they aren't putting a surcharge (no offense to anyone) for obesity, high cholesterol, diabetes type 2, etc. What about unprotected sex (happily married), do I sign a waiver for that too? ok, that part being sarcastic, but makes you think doesn't it?
I remember a time when if you had HIV or AIDS you couldn't even have a job........remember that movie with Tom Hanks "Philadelphia"? So heart-rending. I remember a time when insurance companies even at workplace plans could exclude you based on pre-existing conditions.
My insurance premiums DOUBLED at my small workplace once.................2 reasons, our boss had a heart bypass and 35% of the women (it was a young company) had babies that year, and some of those pregnancies involved complications both before and after birth. I was perfectly healthy and not having babies at the time. Sometimes life isn't fair but thru political, legal and other means, things often can be moved to being more fair . Sometimes we are on the receiving end sometimes on the giving end. I certainly didn't hold it against my boss that he had a bad heart, nor my pregnant co-workers who wanted to have a family. Sometimes we just have to cover for each other, that's what living in *civilization* is all about. There are other needs, and other voices to contend with.
It does suck this happened to you, but this too, shall pass IMHO Stay politically active, etc. and do it in a righteous way with courtesy and aplomb.