My friend way playing a 4e fighter (in the PHB only era of August 2008). His two at-wills were Tide of Iron and Cleave.
He was in town when a mugger (a level 1 brute) jumped him in an alleyway. A level 1 foe vs a level 1 PC mano-e-mano in a 20-by-20 area. Should be easy?
He missed with his encounter power, and since there was no other foes, used Tide of Iron to push the enemy back. Unfortunately, he didn't have his sword with him, so he was relying on a backup dagger.
Every round, he used Tide of Iron, hit, and did 1d4+3 damage. To a foe with 30 hp. He Tide-of-Ironed the guy seven times (not counting misses), pushing him clockwise around the room (did one and a half walls before the guy fell).
The absurdity of watching a guy get pushed along 1 and 1/2 walls of a room was enough to call it a night for that game.
First of all, it sounds like this fight took about 10 rounds if not more - in other words, roughly a minute. If you can't imagine people moving 30' or so in a minute then I invite you to watch any action movie or maybe a boxing match or two.
Second, the player explicitly chose to use Tide of Iron. He could've used a normal basic attack with the exact same chance to hit and damage. In other words, he shoved the enemy around
on purpose. Don't blame the game for what the player chose to do with it. People have many options available to them besides just using the abilities on their sheet.
Third, the stats of monsters (including level 1 brute muggers) are made with a certain function in mind: to provide a fun challenge for a party of PCs. A single fighter with just his dagger is no such thing. It's a (minor) failing of 4e but it simply doesn't do duels like this well, it's an action-adventure game built around a party. The DM never should've done an encounter like this.
Fourth, what kind of alleyway is shaped like a 20 by 20 foot room?
Fifth, even if our hypothetical cube-alley is shaped like that, a 4-square by 4-square battlefield is
far too tiny by 4e standards. And too boring as well, as it sounds like there was no special terrain, no features to make use of, nothing to stunt or improvise with.
All in all it sounds like an encounter custom-tailored to make the least possible use of 4e's strengths and focus on hitting the weak spots as much as humanly possible. A skill challenge to notice a pick-pocket in time, chase him down, and intimidate him into giving you some of his stash would've been easier to do, more in keeping with the game's intended use, and loads more fun.