Daily Discussion: Why Has Fire Spirits Seen Less Play?

I have personally been wondering why this is for awhile now.

Fire Spirits used to be incredibly popular, Hog Rider, RG, Mortar, decks used to run this card a ton, now Hog Rider decks rarely use them anymore.

I think a big reasoning for this is Electro Wizard, as dropping an Electro Wizard behind a unit that the Fire Spirits were behind is devastating, and can completely ruin a push.

Why do you think Fire Spirits has a drop in play? :D