The observatory grounds were set aside decades ago. Yes, they should and will tear down the older telescopes. That is what astronomers do when they locate an observatory on an ecological reserve. It is also why they severely limit visitors to the summit. That and the fact that it takes hours of conditioning to go there without passing out. Thankfully they have bottled oxygen at the summit if one starts to pass out while worshipping volcano gods. Thank the observatory for that. I doubt that many volcano god worshippers trek to that altitude, which kind of undermines their claim.
No astronomers work there. Only the staff who are necessary to operate and maintain the scopes go there. The astronomers work at 8000' lower down the mountain where people do not need supplemental oxygen to keep from passing out. And now, thanks to the Intertubes, one can operate a world class telescope on Mauna Kea from California, so the Hawaiians do not even need their precious islands sullied by those filthy astronomers.
Meanwhile, protesters are attempting to block the best location in the Northern hemisphere for visual astronomy because of volcano gods! Who said the volcano gods don't want people learning about the universe? They call it an abomination? I call it a celebration.
And yes, astronomers take this stuff very seriously. It is just that the protesters have not made a convincing claim. That, plus the observatory has been there for decades, and it is unique in the Northern hemisphere. There is no better place for this. Period!
The claim of a telescope as desecration is absurd.
Yes, the older scopes can and should be removed. But if the protesters continue, arrest them and build the TMT anyway.