Obviously the right of people to live is very important. But if somebody encourages them to end their own life, their right is not being taken away, they are just being given bad advice. If they choose to suicide, their right to live is being surrendered by them, by their own bad choice. Taking away somebody's right to live is murder. Encouraging somebody to do something stupid is harmful, but it is not murder. No more is it theft if I encourage you to set your money on fire and you do it. You choose to follow my obviously bad recommendation, you choose to set your own money on fire. That is your choice and your responsibility.

Making any sort of speech illegal is a slippery slope. Most civilized people would agree they don't want to read racist rhetoric, encouragements of suicide, etc. but when 'I don't want to read that' becomes 'I don't want you to be allowed to say that' you start forcing the morality of the majority on everybody. And that rarely ends up in good places, historically speaking.