Actually that's not a bad decklist, haha. Technically, his decklist is more consistent than yours, but can it keep up attacking every turn? Here is a breakdown of a 'cheapo-style' no-tech Groudonk assault:
Opening hand is Groudon, 5 Fighting Energies, and a quickball/roseanne's/bebe's/pokeball/greatball, etc.
Turn 1: Drop Groudon, attach energy, drought for 2 more. Hand size is 7-1 - 1 -2 = 3
Turn 2: Draw a card(4). Use your pokedrawing cards as late as possible (to minimize bench damage). Drop another energy(4 on groudon, 3 cards in hand), strike for lethal on something (prize draw, 4 cards in hand).
Turn 3: Draw a card (5 inhand). Drop an energy on groudon(3 on groudon, 4 cards in hand), strike for lethal on something. Prize draw (5 cards in hand).
Turn 4: Draw a card (6 in hand). Drop an energy and drought (3 in hand, 4 energy on groudon).
Turn 5: Draw a card (4 in hand). Drop an energy and attack for lethal on something. Prize draw. (4 cards in hand, 2 energy on groudon).
Turn 6: Draw a card (4 cards in hand). Drop an energy on Groudon and Drought (1 card in hand, 4 energy on Groudon).
Turn 7: Draw a card (2 cards in hand). Drop an energy on Groudon and strike for lethal on something. Prize Draw (3 cards in hand, 3 energy on Groudon).
Turn 8: Draw a card (4 cards in hand). Drop an energy on Groudon(4 on) strike for lethal on something. Prize draw (4 cards in hand).
Turn 9: Draw a card (5 cards in hand). Drop an energy on Groudon(3 on). strike for lethal on something. Prize draw (5 cards in hand).
That's game : D.
Thats not even including possibilities of cards like Buck's Training, Pluspowers, Professor Oak's Visit.
Etc.
You win. It's very consistent.
It's just really simple, so people don't like it. Using warp points makes it even more disruptive.