TL;DR: Good/complex cards are rare so they're special so you'll buy more packs. BUT I agree I'd like to see the overall quality/usefulness of cards go up.
Except its been known for a while now that most sales of Pokémon TCG product don't go to people that actually play the game.
No, not collectors either.
Basically people (guessing kids) that get the cards because they are Pokémon cards, but never learn how to play or collect proper. Such "customers" outnumber players by a huge margin. Before anyone says anything, no it does not make sense to tailor the game to these people: they just need cards that say "Pokémon" on them to be happy. There is very little risk of alienating them by focusing more on collectors and/or players.
Keep in mind I'm not suggesting that we get rid of higher rarities either... just don't make them cards only available in that rarity. Full Arts are a great example... at least the Trainer ones, where an Uncommon card also has a wonderful Full Art version for collectors to chase after and for random little kids (...and me) to enjoy for being shiny! OoO