LFR is a source of progression for those with limited time, those who can't put weeks into normal or heroic mode raids.
You haven't still answered why the Ilvl must be better than 5 man heroics when the effort and difficulty is the same.You could keep the purple text on it so people feel better. Or make 5 man heroic loot the same as LFR (from 463 to 476).
Those who do have the resources to do so can do LFR in addition to normal mode if they want to, and thus end up with better gear in return for the extra effort of beating harder content.
You still miss the point that I, and many other are forced to do LFR for the gear upgrades to perform better in raids. Don't start with the "you can choose to do it or skip it" crap. Why would I want to perform worse than I could.
EDIT: Sorry for answering in many comments like this but this site is updating really slowly :(
You personally feel the level of effort required for 5-man heroics is the same as LFR. That's your opinion, many disagree.
And yes, LFR is a choice whether you want to admit that or not. Obviously, if you want to be able to get through normal mode as efficiently as possible, then you'll want put in the effort to get your LFR gear, but it's by no means essential.