I agree that there is a steadily increasing disparaity between average PC initiative and monster PC initiative as level increases. While there may be an argument that it somehow "balances" team monster vs. team PC because it allows monsters to actually get in one round's worth of actions before being nuked, it does seem quite counter to the general direction of 4E over the years. We observed increasing disparity between average PC attack rolls and average monster defences, and a whole slew of mechanical fixes were put in, specifically the various (and now multitudinous) Expertise feats (if you can't find the perfect one for your PC's combination of weapons and implements, just wait for the next Dragon mag...), and superior implements, superior weapons. We observed increasing disparity between average monster attack bonuses and averge PC defences, and a whole slew of mechanical fixes were put in, specifically the Improved and Superior defence feats, armour specialisation etc., and magical armour being "automatically" masterwork (i.e. increasing in base AC bonus as it increases in enhancement bonus). There are some mechanical fixes for disparity between average PC initiative and average monster initiative, but they are fewer than the other numbered-fixes on offer, and in any case they simply become further feat taxes or require particular PC design choices. It would be nice if the system itself didn't lead to these results in the first place.
NB There is a suggestion in one post above that Int it relevant to Initiative. Of course, it isn't. It's one of the few instances in 4E where only one ability affects one attribute, whereas most attributes are affected by the highest of the two abilities in an ability "group". The other major break with the ability-group-affecting-a-single-attribute is that only Con affects hp and number of surges. Which is why Con is never, ever, a dump stat, for anyone. And why Int is usually dumped for Dex in any trade-off between the two. Again, a particular design choice for which the rationale is obscure but the game effects are significant.
Cheers, Al'Kelhar