Man, I can totally get folks not liking 4E, or that they find other editions better capture the feel of the game they are going for or whatever... but posts like this just come across like someone looking for things to argue about.
(And props to Spinachcat, of course, for his own 'classy' insults aimed at games other folks enjoy.)
I genuinely understand why some folks don't like 4E. But I don't think there is a single criticism in the OP's post that has a shred of genuine truth behind it.
1) Folks not having played 1st Edition. Yes, many gamers are younger than you. But 1st Edition happened quite some time ago. I don't know if it is good or bad - I've never played it - but saying it is a bad thing that gamers aren't forced to go back and learn all the old editions? That's just silly. (And, for that matter, based on the same poll, a good chunk have played from 2nd Ed on, and nearly all played both 3rd Edition and 4E.)
2) Yes, you could heal with bards, paladins, druids. None of them as well as a cleric. Many groups felt you 'needed' a cleric. Mearls is saying that 4E addressed that situation - and it did, in multiple ways. No bending of the truth is going on here - at least, not by Mearls.
3) You've missed the entire point. The issue isn't whether healing should be in the game - it is whether you should have it tied up in a single character (or, even worse, a single character who has to play a specific class and build) in order for the group to have a chance at success. You want to see something that looks like an MMO? That is it! Mearls is advocating a game where, rather than having to say, "We need 2 DPS guys, 1 Tank, 1 Healer" (or, to translate, "We need a cleric, a rogue, and wizard and a fighter"), you could instead have pretty much any mix of character concepts and have a good chance at success.
Now, feel free to object to specific implementations they have taken to get there, but don't say that this idea of building to allow more flexibility in character choice is inherently a bad thing, much less somehow inherently like an MMO. It has nothing to do with an MMO, and every time you gesture that it does, without any rationality behind it, you only serve to weaken your own argument.
4) Classes, yes, still define what a character is capable of. That comes from a combination of powers, yes, along with skills, proficiencies, and class features. Rogues move quickly, hide well, find traps, and stab things in the weak spot. Fighters are big and strong and hit hard, and get in enemy's faces. Clerics heal and pray and smite undead. Barbarians rage and climb and beat things in the face. Etc.
Saying that a 4E Barbarian, who rages 3 times a day because he has three (distinct) daily powers that let him rage, is somehow different from a 3rd Edition Barbarian who rages 3 times a day because he has a class ability that lets him rage... is, again, silly. They found a common mechanical system they could use to represent the different iconic abilities of various classes. You don't like the system - that's fair. But dismissing powers as being entirely divorced from their classes is, honestly, a willfull misreading of the 4E system.
5) Saving throws. Instead of rolling Fort, Ref and Will, the DM rolls against them. Six of one, half-dozen of the other. This is a change, yes, but hardly one that somehow fundamentally breaks the spirit of the game. You don't have to like it, but it represents the same exact thing, and just changes the burden of rolling from one person to another.
6) "One word POWERS instead of spells." I take it you haven't looked in a PHB and realized that Wizard Powers are called spells, right?
The mechanic remains - several times a day, the wizard expends his most powerful spells. Each combat, he expends slighlty less powerful ones.
Overall, yes, he has fewer such spells than in past editions. Vancian magic has definitely changed. But again, insisting it is gone entirely requires actively misreading the rules.