If wizards can basically only fight... wow. That's pretty drastic. I'm not sure I like that.
Others have sort of said this, but just to be clear- 4e is really designed for a group of heroic (the regular meaning, not the 4e levels 1-10) adventurers. That means that they are all minimally competent at basic adventuring tasks- you never need to roll for whether or not you can ride a horse, for example, though taming an animal would be more involved. Most of the rules focus on combat, mostly due to the presumption that a) combat requires the most adjudication, b) players generally shouldn't have to ask "DM, may I?", c) much of non-combat stuff can be narrated and described by the players without rolling, and d) when noncombat stuff does require rolling, it can be done in the form of Rituals (think long casting time spells) or Skill Challenges, or both.
I've described it as a superhero sim before. Think about the Marvel Cinematic Universe, for example. Sometimes the superheroes fight enemies. Sometimes they have to find out information. Sometimes there's a sequence where they have to escape a collapsing structure. Sometimes they have to negotiate with politicians. Sometimes they have to defuse a series of traps or repair stuff, either in combat or out- the sequence in the original Avengers when Iron Man and Captain America have to get the Helicarrier flying again is a perfect example of that. Sometimes they capture an enemy ship, or even take their own ship but have to work together to fly it really competently. All of them are competent in combat, and all of them have their own tricks and skills. And the in-universe rules mean that Doctor Strange, who can manipulate time and space, is really no better at combat and no more useful to the team than Captain America, who...is really strong, regenerates, and can throw a shield. That's the feeling 4e is going for- a Wizard who can lock down a 25x25 foot area easily but can't insta-kill enemies who are there, a Fighter who naturally draws people to focus on him and has some effectively super-human moves but who also is really good at perceiving things, a Warlord whose words can manage to get allies who should be nearly dead to get up and fight, a Rogue who is competent at manipulating objects and who also is deadly with daggers. It's not that Wizards can only fight, it's that Wizards are good at fighting, and good at doing stuff out of combat too, but they're not better than Fighters or Rogues or Warlords or what have you. There's tons of dialogue and non-combat events in the MCU, but there's no one so good or powerful at anything that they outshine everyone else, and the same is true in 4e.
As for Essentials- a lot of the Essentials resources are really useful for O-classes (pre-Essentials), and a lot of Essentials classes can be made to meet baseline performance, often by poaching a power from the O-classes (for example, the Slayer- the Essentials Striker version of Fighter- can use a feat to poach a power from the original Fighter). They're also usually competent in Heroic tier on their own, especially early Heroic. Their features aren't really as good as the powers that O-classes pick up in Paragon or Epic, and if your goal is to regularly upgrade what you do and be able to do new things, they don't do that very well. For whatever reason (trying to appeal to 3.5 nostalgia, maybe), Essentials Mages are an exception to that, because they not only get the full slate of Encounter and Daily slots that the original Wizard (Arcanist) gets, but they can also take the ones from the original Arcanist with their Encounter and Daily slots. If you understood the 4e math and knew how to build characters, Essentials was annoying because it introduced some classes that dragged a party down. If you were a 4e diehard, simplifying a lot of melee classes and giving Wizards new powers felt like bowing to demands from 3.5e players rather than catering to your own. But Essentials feats and powers are fine, and the classes are fine too with the caveat that you either play in Heroic or eschew the ones that are really lost causes (Hunter and Binder- Cavalier is often listed there too, but is competent enough in Heroic).
One other note- 4e was really designed with digital tools in mind and an "everything is core" philosophy. Unlike previous editions, Dragon magazine stuff isn't overpowered. Errata in theory wasn't a problem, because you were going to subscribe to D&D Insider and the digital tools would reflect an updated version. If you didn't own a book but wanted powers and feats and other crunch from it, that wasn't a problem, because you could find them in the electronic tools. Unfortunately, for a variety of reasons, the tools were never fully realized and updated properly, which hurt the edition as well.