If manufactureres know that their products require burn-in time to sound their best, why don't they just design them to sound better in the 1st place?

And when designing their stuff, how do they know if it will sound better after itburns in?

And why doesn't it ever sound worse after burn-in?

Why not have a double blind test with a new and burned-in unit to prove it's effects?

Just my honest opinion, but I believe it's all in the ear re-adjusting to the new sound.