EcoQuest and EcoQuest 2 are Sierra adventure games with a lot of pedigree (Jane Jensen of Gabriel Knight fame worked on the first one, for example) and an environmentalist message that is as current as ever.

Why aren't these games on GOG.com?

Maybe IP rights shenanigans. There are many other Sierra adventure games already here, so I doubt it's a lack of will.

Can't hurt to vote for them in the Community Wishlist:
EcoQuest: The Search for Cetus
EcoQuest II: Lost Secret of the Rainforest

For sure. I've cast my vote.

If they get the games some day i'd definitely buy it for the goddies/to help out GOG.....also I hope if they get them that they get the talkie version of the first game.