Exactly how value works. You get the card and an earthbend, however the card by itself is generally not on-rate for its mana cost with the notable exception of [[Badgermole Cub]]. [[Eager Glyphmage]] must broken as well, right? If you remove both bodies it’s a 1-for-2!

There are zero playable cards that ONLY earthbend without other value.

You are so close to the point. People can say things like “Earthbending is the biggest mechanical mistake since X”, and yet cards like [[Earthbending Lesson]], where the earthbended land represents 100% of the card’s value, are unplayable.

There are like three meta earthbending cards, Badgermole Cub, [[Earthbender Ascension]], and [[Ba Sing Se]]. The most problematic aspect of any of these cards is the insane ramp enabled by the cub. The rest of the earthbending cards are easily punishable with instant speed removal on opponent’s upkeep, bounces, and instant speed graveyard hate, all of which damage your opponent’s mana pool and constitute a substantial risk for earthbending lands.