Honestly, it's been years. I thought by now they would of figured it out and realized it's a good option have put in.
It's annoying making a new world, exploring and building, only to find it doesn't have an Ocean Temple, or even melons, etc.
I have yet to find a seed with every object in the game. Only way to do that is with Creative, but it feels like cheating doing that so I prefer Survival.
The Ender Chest was a good idea, but why couldn't they expand on that.
Terrarria gets it. They made it possible to transfer items on characters between worlds. Why can't Minecraft make a similar simple option or at least an option to spawn a world containing all biomes. I'm a completionist and like to have everything. I don't want to have to make and build several worlds to collect all biomes. I want ONE great world.
Not to mention, you can't get achievements on CREATIVE.
Just make it an option at least, that way it's not forced on anyone if they like having random and incomplete biome seeds.