Medical Hypocrisy

I will never understand why medical science is allowed to be held back by the moral crusaders who seem to believe that, for whatever reason, they have the right to force their opinions onto everybody else.

When we have a section of medical science dedicated to finding humane ways to chemically execute prisoners, doesn't it seem just a little incongruous that people are already trying to ban the use of cloned human blastocysts for the harvesting of genetically compatible stem cells?

why is it perfectly legal for people to promote and sell complete myths and unsound science as valid medical treatments yet it's illegal for the known benefits of illegally classified drugs to even be subjected to scientific scrutiny, let alone used as treatment options. 

Why is it that we can walk into health stores on the high street and buy homeopathic "remedies" (which are, basically, water that's been slapped about a bit!) for potentially life-threatening ailments when scientists are prevented from carrying out research into the multiple claims that Cannabis oil can be (and has been) used to shrink cancerous tumours without the need for chemotherapy?

Or why we can legally promote and use dangerous dieting techniques that put copious amounts of strain on our internal organs when the greatest failing of drug rehabilitation programs is that medical professionals are not allowed to use illegal substances so must first switch patients onto a legal substitute (many of which are more addictive and more harmful than their illegal counterparts)? 

What kind of world are we living in, where it's perfectly acceptable for quack science to offer false hope and empty promises to some of society's most desperate and suffering when we put stumbling blocks in the way of real science making potentially monumental medical breakthroughs on the basis of the attitudes of a narrow-minded few?