Why are people so accepting of euthanasia for suffering animals but not for suffering people?

That word we use when we put a suffering animal out of it's misery is HUMANE! Doesn't make sense does it! Some religions say it's a sin to commit suicide, whether by their own hands or by the help from someone elses! There are some religions who committ suicide in the name of their God!! Taking innocent people along with them! So, whose right and whose wrong? There are some people who kill themsleves in a moment of depression. Those deaths are considered tragedies, with little stigma attached to them. I think one of the reasons humans don't condone suicide is, another word, HOPE! People hope someone will find a cure for whatever ails them, and you are right about not letting go of a loved one. We humans are strange creatures! We keep comatose patients alive for years, again, for who? Me? You? If life is so precious, why are we killing each other with bullets and bombs? An animal knows when it's time to die, and goes off somewhere quiet to do so, with dignity. Not so, us humans! WE have to prove WE can master death with all the drugs we pump into our bodies! And the funny thing about all our beliefs! we STILL die! People put RIP on tomb stones. Why didn't they let the person RIP BEFORE he died!?