They are not the same, but they share two key properties: their danger and potential addictiveness.

Most people would not even seriously consider making extreme sports illegal, despite their danger and potential addictiveness, but it's those very same properties of some illegal drugs that are most frequently cited as the primary reasons for making them illegal.

If those are honestly the main reasons that so many drugs are illegal, then why not make extreme sports illegal as well, for those very same reasons?