Because Europe has a history of murdering or forcibly sterilizing disabled and mentally ill people. Because the capitalist state wants to spend as little as possible on welfare. Because just killing people who cannot generate a profit for capitalists is the cheaper option. Because we can see what is already happening with "assisted suicide" in countries like Canada.

my country (Sweden) had mandatory sterilization of trans people until the big 2013 - but worry not, we have come a long way and it is amazing how much can change in 10 years (we are worse now)