In the smoking sense you are right. Smoke will be bad on lung tissue regardless what kind of smoke it is. However many cancer patients have used edibles or vapor in an attempt to avoid the harmful smoking aspects but still get the medical benefit of the THC. So there are always other ways to make the use "healthier" on some level. It may not ever be completely "healthy" for you, but not much is these days. All the chemicals we're exposed to in this day and age are harmful as well not to mention the regular use of alcohol and tobacco, and even down to the GMO's present in much of our food supply.