It's sortof like clearcutting yellowstone national park (or some other place of natural treasure) for a large pork-barrel project which can be done anyplace else.
The fight is not just on sacred land grounds, but on the environmental impact assessments. Just because politicians want to ram a project through and bandy about the term "science", does not mean we should support it. It seems like this area is a treasure of biodiversity and preserving it benefits furthering of human knowledge possibly more than the telescope.
I'm curious why no alternative sites are considered. I suspect this is not because of advantages of the site, but because some organizationall well-placed scientists (not from hawaii) want to have their funding organizations send them to Hawaii regularly.