I can disprove part of this arguement... the math part...
the argument goes something like this (I admit i do not belive it so i may mess it up a bit) at level 1 PCs have +x to hit and monsters have Y def, at level 30 the PCs have +x+26 and monsters have Y+30 so the PCs lose 4 pt as they level (5 if there epic destiny does not increase a stat).
Now here is my point... that is so short sighted. See at level 1 my swordmage has 2 at wills, 1 encounter attack, 1 daily attack, and 1 encounter race power. He has no magic items, and only 1 feat (2 if human)
at level 11 that swordmage has atleast 2 new paragon path features, 3 daily powers (most have miss effects, but some may be reliable) 4 encounter powers, 2 utlity powers, and those same two at wills. 7 feats, and most likly atleast 5 items. even if only half of them have powers of there own it is atleast 2 other powers.
A fight at level 11 is very diffrent then a fight at level 1. Infact you mostly have more fights per day too. Now from my own (very limted) experance, at level 1 you range from 1-4 encounters per day with most beign 1 or 2. At level 11 you have 3-4 fights per day with maybe 3 or more other encounters added in...
at level 21 the game changes even more... epic destinies, a few more powers...and bunch mor eitems and feats.
in order to truely do that math out, you need to have avrage PCs and figure out what a true avrage increase is... I tried once to make a level 1 fighter, level 2 fightger, level 3...all the way up to 30 useing the money for creating high level characters.
I found the math was way beyond what I can do. In fact The real problem became synergy. I finaly decided that the only way to do this was to play 30 levels with 5 genric pcs following the parcel rules to the letter...then record the results of each level in both numbers and opion.,.
in the end I decided that we had to go with what we all saw, but what we saw was diffrent. the math was to complex and some of us saw easy mode others saw hard mode...
infact I have seen in the same game, a 20 wis with expertise full blade avenger and a 16 str kopesh non expertise warlord, in the same game as an 18 int 16 dex accurate wand wizard, in the same game as a fighter with a 16 str, and longsword. talk about running the gambit.
avenger at 1st level +9 2d20 rolls
Warlord at 1st level +5
wizard at 1st level +5 vs NADs
fighter at 1st level +7
guess who the only person who ever complained the Def were too high... the avenger.
at level 8 the avenger had a +3 weapon, the warlord was still useing a +1 and the warlord not once complaied about missing... mean while when the warlord had lend might (+1 to attacks he grants) useing warlords favor (+4 to ally attacks) then action point for commander strike on the avenger in flank, the avenger had +24 to hit... the warlord had +13 to hit... the avenger rolled 2d20...
[sblock=monster]Dragonborn Gladiator
Medium natural humanoid , dragonborn
Level 10 Soldier XP 500 Initiative +9 Senses Perception +6
HP 106; Bloodied 53
AC 24; Fortitude 23, Reflex 20, Will 21
Speed 5
[/sblock]
i remember this fight well... becuse with the avenger needing anything but a 1, after the fight he still complained that the monster was too high level...and the warlord player told him off in a huge like 5 min rant about how he needed to grow up...
that game made it to 23rd level and we could count on 1 hand the number of times that avenger missed with aan attack... the warlord and fighter never took expertise, although the fighter did go kensi... so i guess that counts for something...
I have also seen rouge dagger masters with 80%-90% of there powers targeting nads... infact i can in theory buid one that only has 1 at will targeting AC