Universal Access is am important goal, however, it does not trump environmental impact.
Unesco has spent a lot of money making world treasures more accessible to persons with disabilities, but only when doing so would not create an environmental or historical crisis. Unesco has not declared this project to be an environmental crisis yet, but they have expressed concerned and are asking for studies.
by and large, groups like the UN Committee on the rights of persons with disabilities and the international council on independent living have agreed that they share the goal of universal access, but not at the cost of undue burdon on business nor risks to public health and safety nor significant environmental or historical damage.
I am not saying that this tram will or will not cause such damage, I do not know. However, it must be factored in and there are many in the mix who do believe it will cause such damage.