Power creep is a seemingly inevitable consequence of game development. No matter whether it is a tabletop RPG, an MMORPG or even a RL sports team there is a constant trend upward in power. In an MMORPG the reasoning behind this is obvious: Much of the incentive to do anything for characters is increasing their power and the increases need to continuously ramp up to keep people's interest. Doing 1 more damage is pretty great when I am doing 12 damage but when I am doing 12,000 damage I need to do 1,000 more for it to feel significant.
WOW illustrated this just as all its predecessors did; characters using the most current gear would utterly demolish any challenge that appeared years ago. It isn't all gear of course as you can easily see by looking at WOW's addition of profession perks, glyphs, reforging and dualspeccing. Even though all of these were added in to either fix imbalances or create new and interesting decisions they all drastically ratcheted up the power level of characters. Every time something new and impactful comes along everybody gets better. This is really obvious when looking at level grinding in WOW at the moment: Characters have good talent trees and reasonable resource mechanics, get many more abilities at lower levels, have glyphs and have heirloom gear. All of these things (perhaps save heirlooms) were added in to improve the experience and make characters more fun but they really powered everyone up. It is true that hunters using mana and paladins not having any way to attack the enemies were stupid mechanics but removing them has raised the bar forever.
DnD 4th is no exception here. My group has been exploring using the online character generator and the extent to which our characters are better than the basic Player's Handbook characters is astounding. First off there are lots of feats that don't suck! Instead of running out of things to take at level 6 as a caster I will have constant and interesting tradeoffs to make right up to level 30. Everything I take will be good and there will always be a reasonable alternative. This is great of course but it sure does make me more powerful. There are also Backgrounds and Themes which are completely new aspects to characters that add ridiculous powers. A Background will only either add a skill to your class skill list or give a +2 to a skill but that is still a straight up buff with no penalty whatsoever. You can't balance numerical buffs with 'roleplaying challenges'. One ridiculous Theme even lets you increase an ally's attack roll by 1d4+2 as an encounter power. The silly thing is this isn't any sort of tradeoff since you just add that power to your list. Even if you had the option to trade in this power for something else it would be a buff because of increased choice but to just get it for nothing is ridiculous.
The point of all this is to fool the audience really. Everyone wants to see their characters / favourite athletes / toons get better but if a flat out +2 to everything is announced it would be roundly booed. Instead companies need to increase the power level of the game by slipping in changes that seem at a glance to be innocuous but end up being really impactful. Football players need better equipment and training, WOW characters need to be able to glyph their abilities to be better and DnD characters need 'themes' that flat out make them kill monsters better. It is an unfortunate but it works so it is unlikely to stop any time soon.