True, there are cards now where you instantly win. several, in fact. The thing of it is is that those cards are mostly sorceries that can EASILY be countered. Any random "I Win" card is not NEARLY as powerful as ANY of the various and asundry overpowered combos in the current Type 1 Environment, or and of the GROSSLY overpoered/undercosted cards in Urza's block, or Exodus expansion.
Case in point (and one of my favorite cards):
Coalition Victory
3WUBRG
Sorcery
If you control a basic land of each type and a creature of each color, you win the game.
Do you have any idea how hard it is to do this in the current environment?
Admittedly, things started getting pretty sucky after Ice Age. However, the most recent block, Odyssey, is great. The block before it, Invasion, is PHENOMENAL. In spite of a few "I Win" cards, these last 2 blocks have really shifted the focus of the game from locking your opponent down (thusly BORING him to death) to flat out kicking ass, whether with direct damage or beatdown.
Magic is hella fun. I didn't come in until Mercadian Masques block (yuck). I curse my friends every day for getting me into this game.
Steve Z