Keep in mind a Paladin can crit maximizing the damage. A fireball can't.
For 8 more points of damage on one foe. Still, nowhere near the ballpark of 100+ points of damage of the wizard.
One of the things we didn't have for playtesting was guidelines on how long the adventuring day was. That may have contributed to the feeling that the Paladin could always dish out some big damage as I tended to keep encounters low but with high difficulty. Between the PH, the Basic rules, and some previews of the other books, I think guidelines exist on the adventuring day which may also reduce this issue.
Personally, I prefer 6 or 8 or even 10 encounters per day. Hence my minor issue with 5E healing. I want 10th level PCs to wade through a dungeon, and not be stopped and go home by encounter 3 or 4.
If a DM does up PC healing, then the Paladin mega-hits won't seem as impressive (especially if he does 44 points of damage to a creature that only has 30 total or remaining).