Because you can be happier with better things. For example, if you never tasted adult foods you'd still be "happy" eating baby food, and be completely unaware that you're missing out on greater happiness available from other foods.

Upthread the point's made that this means you'll be dissatisfied a lot of the time, and that's true. But when you are happy, you'll be happier.

In the context of the article, you might have to drink crappy coffee from time to time, but when you get great coffee you'll have a better drink experience than somebody with no palate will.

From Calvin and Hobbes: "I find life gets a lot easier if I lower my expectations to the point where they're already met".

I used to think it was funny, now I wonder if that's the secret behind Buddhism.

I think it's in our nature to seek out better options in everything in our lives.