Because college Foggy would be like "C'mon, my best bro and my girl, let's all be buddies!!!" With college Marci thinking Matt is obviously hot and smart but there's also something a little *off* about him? And college Matt is all "uggh I can tell Marci's blonde without seeing her, you're too good for her, Foggy" but he also underestimates her. And clueless college Foggy Bear is clueless but he's also too perceptive about them both.

Bonus for post-series epilogue with either Matt/Foggy finally getting together or Foggy/Marci back together, and Matt and Marci finally go, "Okay, Foggy had better taste in you than I thought." Plus if Matt/Foggy then Marci is all "I KNEW IT!"