Well, through the years I have played more spellcasters than anything else, so I obviously have a bias. I agree that sometimes the D&D magic system is annoying or limiting, but that is why I used to play other games as well. I take the D&D system for what it is and enjoy it. As for the "Tenser's Floating Disk syndrome", I guess it depends a lot on what kind of D&D game you play. If you play a combat heavy game, you are correct that the spellcasters will load up on offensive spells and things will start looking like a video game. Of course there are a lot of video games out there where the players just carry a big sword and hack apart everything they encounter, yet I do not hear as much that the D&D combat system is too much like a video game (yes, it can be, but again it is what the DM makes the game).
So what makes a D&D game less like a videogame? Its about the NPC interactions, the roleplaying, the solving complex challenges without necessarily killing your way to the solution. That happens regardless of the magic system in use. When I play spellcasters in these kinds of games, I take a few "blaster" spells, and many spells that can be used in creative, flexible ways. It does take a lot more thinking and planning, and yes there are times where I am frustrated that I do not have the correct spell for the situation, but if I were playing a fighter, I also would not have the spells I need. The only thing more I would have as a fighter would be the ability to dole out and take more damage, so if that isn't the answer, then my character should be just as capable as any.