I like Lucario for multiple reasons.
Surprise Factor. If the opponent looked at my hand and saw a lake bounday, they may shuffle it into my deck, or may play differently. But if all they see is a SP dex, or roseanne, or great ball, they won't know what to expect.
Easy to grab. If I need the double weakness now, I can just roseanne/bebe/luxury/sp dex/great ball/etc for it and drop it. You can't search for a stadium with ANY trainer/supporter.
It's SP. Meaning that you can Poke-Turn it if you don't want your opponent using it or if you start with it. It means that you can Energy Gain it and possibly attack with it for 2 energy. It means that you can grab it for free with the SP dex coming out in the next set.
It's basic. Minus the bad start with it in non-SP decks, it's a basic, so it doesn't require resources to get built and useful. I can grab, and drop the same turn I need it. The useful of a tech can be quite different if your comparing a stage 2 like Dusknoir (that you need rare candy, and possibly 2 supporters to get both stages) to a stage 1 like Dugtrio (don't need rare candy, but still need 2 supporters to get both stages) to a basic like Lucario GL (just need 1 supporter, or possible trainer to get).
I don't see how there is any "hype" over it, though. It's purely, 100%, a metagame card. At Battle Roads, nobody will know what to expect, and any uses of Lucario will be failures as long as people aren't playing the same decks that were being played at Regionals/States. At Nationals, it will be more useful, but not to as big of an extreme, as people are going to try new secret deck ideas to surprise the big field for the surprise factor advantage.