LFR isn't really designed with that whole paid premium living campaign thing in mind. It was rolled out to be accessible, though its accessibility is now trumped by Encounters.
While I can't really speak to what was planned at the outset of LFR, I don't know that accessibility was one of its original goals, so much as it is/was intended tobe for 4E, what Living Greyhawk was to 3.X.
If you mean accessibility from the point of view that you can play it everywhere (in a store, at home, at a convention, in a library) - then certainly, yes, that was a goal.
One of the biggest hallmarks of LFR is that we (try to) support everything that WotC has published for 4E. PHBs 1 - 3, Powers books, Encounters, D&Di Content - come one come all, and we'll take you! Bring us your Revenant (Warforged) Cleric of Pelor (a running gag - and yes, perfectly campaign legal), he can sit here next to this nice Hexblade for a few hours.
Another is that, as a Living campaign, you can play through every level of potential play - if you work your way up to the Epic Tier, we're still there for you.
Essentials, by contrast, has a design goal of being the preferred entry path to 4E Organized Play. It only allows Essentials characters, only plays in stores, and only supports levels 1 through 3(ish). At least officially, many GMs wave the Essentials requirement, some play outside their store, some skip the Wednesday Night requirement - but by design these are the intended rules.
This isn't to say one program is superior to the other - instead they're options for people who might like to play different "flavors" of D&D, just like the <Name Not Released> new program will be later this year.