I think that several factors (other than religion) comes into play as to why euthanasia and the right to die is forbidden, illegal, and/or outlawed in many jurisdictions and countries around the world are due to the fact of secular humanism (the concept that life is good and life is valuable while death is not), mental illness and irrationality, and some other unspoken reasons (people might acknowledge and know but they don't really say it out loud) such as being alive for family and others (selfishness of others that they project onto others who don't share their opinion, values, views on life), and of course, government wanting it's citizens alive (regardless of whether they are miserable) in order to keep society (a sick and fucked up one at that) to function.
As for abortion, there has even been an argument that before a certain stage, it is not considered a 'human' being or a sentient being at all. Of course there are religious people and conservative people who would argue against it and all that, but I digress.