life on Gotland is way more interesting due to the tourism

Perhaps those people don't want "a little more people there", and think their life is enough interesting as it is?

Personally I think the anti-tourism mindset is stupid and that is what I was trying to convey in the text.

Try living in some places burnened by tourism and see how bad it gets. And consider how Gotland might be in a trajectory to get in that list, as welcoming tourists can easily cascade to further tourism and changing the local economy, and then it's a race to the bottom.