Euthanasia costs lives. Not only do doctors kill people who ask to die–generally without even attempting suicide prevention services–but the ethics-altering values of euthanasia/assisted suicide devalue despairing lives generally.
For example, several years ago, a woman named Kerrie Woolterton in the UK swallowed anti-freeze and called an ambulance, the latest of several such suicide attempts. But she pinned a note to her blouse refusing treatment. Despite the medical ability to save her–which had succeeded with Woolterton on previous occasions–doctors honored her “choice” and just let her die (painully) over a 24-hour period.