The idea that a race could be working so closely with druids over the years/story, could still never become a druid is about as anti lore and RPG as you can get. It literally breaks the idea of time passing and changes occurring.
And this is a very good point. Now if this was reflected in the game amongst the NPCs (the goblin druid comes to mind) as a change in culture, this would help matters.
Reflect it in the story.
I can sympathize with the wanting to be different when there are restrictions. In D&D, if someone wanted to be really outside the rules (for example a class that a race doesn’t support) the GM in our games would likely allow it and NPC interactions would be what you’d expect for that character because they ‘different’.
Your example was a good one too. It’s the game that is lacking and sometimes it feels that they add random pieces without putting things together.