Since Blizzard implemented their current gearing model in early WoTLK the item level gap between the best gear available to raiders and the best gear available to non raiders has been getting wider and wider. The addition of flex and LFG, the removal of valor gear, and going from +7 I level heroic increase to +13 have really kicked the process into high gear in MoP.
Take for example patch 3.3. A player with full BiS ICC gear would have an average ilevel of 277. A BiS player who never set foot into a raid would have 261. This is a difference of 16 item levels.*
Now, in MoP a character with full BiS LFR gear + legendary cloak has an average ilevel of 543 (550 if they have full burden of eternity gear), while a player in full BiS heroic SoO gear has an item level of 576 (583 if full war forged). A difference of 33 item levels*.
So, in two expansion's time the difference between a raider and a non raider has more than doubled*. Yet everyday I see people on this forum complaining that casuals now have access to gear that should be exclusive to raiders. Why is this?
It can't just be because non raiders have access to "purple" gear, as that has been the case since they implemented the PvP system in Vanilla (the origin of the term welfare epics). Is it really just because LFR allows players to see the content?
Also, for the first time there is content in the game where non raiders really need high level gear, the top tiers of Brawler's Guild for example.
*: Blizzards ilevel formula calculates a roughly ~10%** increase in stats for every 13 item levels. Thus you need to look at absolute values rather than percentages to see the actual difference in character stats. Also keep in mind that most secondary stats serve as force multipliers rather than linear additions, and thus character power actually scales faster than the stats alone would indicate.
**: The actual number looks to be about an 11.1% increase (or an 8.8% decrease if going down instead of up) but may very SLIGHTLY based on rounding and sockets.
Edit: D'oh! Forgot to factor in crafted 553 belts and leggings. Updated my numbers to reflect this.