I can see where he was coming from. Wizards have button-awesome solution to most problems that could normally be solved in a more creative way. "A hug chasm? Lol, I'll just fly over it. An important NPC is dying and we need to get him to a healer? Haha, I'll just teleport this fucker. We are in an unknown location and need some way to find out where? I'll just scry or whatever. We found a mysterious powerful sword, should we use it right-away or maybe find someone know might know something about it. After all it can be cursed. Just let me identify this junk". I understand that he could look down on players who instead of relying on their wits when travelling through dungeons just preferred to shout "I cast fireball!".
Thing is, thats not how you played wizards, not even at high level. The castings were far more limited, you were defenseless without them, you couldnt really take a hit and even your best spells could be saved against. Saving throws went up meaning your spells actually got weaker against strong opponents instead of scaling to an ever growing stat. Even a single point of damage while casting would interrupt it and youd lose the spell, you didnt get spells per level, so you had to actually go out there and explore, and it was entirely up to luck what you got.
Playing a wizard on OD&D and AD&D was very, very different, it relied on staying on your toes and constantly relying on your team mates for even the easiest of tasks, even at high levels. Today playing a wizard is easy mode and requires no thought at all.