Those keyboards are designed to be used with your thumbs while holding it from the side. They don't really function any other way. You can't reach the keyboard from the side because of the width of the controller. There's no possibility whatsoever that the device will balance if you hold it from the bottom where your thumbs could theoretically reach, ignoring that your thumbs also don't bend that way.

It's quite possibly the least ergonomic device ever made.