No one said it was? No one’s bringing up rating, the conversation is about nerfing a racial. The point is Shadowmeld has more utility and use cases compared to other racials, plain and simple.
That’s true for most of the older core races, not just Night Elf. Almost every non Allied Race has weak passive racials, with very few exceptions (like Orc Hardiness, which was nerfed).
Also how are you going to bring up Berserking when it’s been nerfed so many times throughout the game 
It used to be 30% haste on a 3 minute cooldown and now it’s 10% Haste. Our passives weren’t the greatest either yet it still got nerfed. Like, look at this crap:
These are way worse passive racials than Night Elf has and yet Berserking got the nerf bat. Shadowmeld remains untouched though despite being one of the most powerful and versatile racials out there. There’s a reason they make up 30% of the rated PvP leaderboards and more than all Horde races combined.
And yes, I know I’m bringing up rated PvP here, but that’s because it’s the only data we have to reference. I’m wiing to bet though that if it’s dominating at the highest level of play, chances are the same trend exists in PvP as a whole.