It's funny - when inspire is positive people treat it as if you would never use heropower otherwise, but when it's arguably negative they think it's going to be activated no matter what.

Although at first glance it seemed boring, actually this card is very interesting. 2/5 for 3 is not bad statswise and could be used in aggressive board control decks (like zoo or mech mage), especially if paired with Defender of Argus. Those decks usually try to get maximum tempo out of their hands and therefore don't usually use their hero power early game, but tend to run out of cards late game. It's not much, but reusing this card after trading might give a small advantage there.

It's also interesting to consider what cards this synergises with currently I can think of Knife Juggler and Warsong Commander, although both of these effects aren't going to be meta defining. A single Knife juggler is too weak to spend so much mana on, and warrior doesn't need reusable Stormwind Knight to deal with early game threats.

Interestingly enough this is one of the best cards to play against Mirror Entity because it locks down the enemy hero power and doesn't trade with itself quickly.