It really IS necessary to make the game make sense. You can either pick tons of options that give you some new capabilities and have loads of different things you can do moderately well, or you can zero in on a few things you do extraordinarily well and continue to excel at. That's where the interest comes in. YOU the player constantly have those choices to make, so that you are really actively shaping your character. If you just flick switches to be good at X, Y, or Z and that's it you can forget about it and go on to the next thing then it is nothing but a checklist and inevitably there will always be a list of the best options to check off.
I basically disagree, mostly because the definition of "good" has changed. The difference is between "you can achieve a hard DC about 50% of the time if you're trained and have a good stat" to "you can achieve a hard DC about 50% of the time if you're trained, have a good stat, spent a feat on Skill Focus and/or took a race that complements the skill in question and/or have an appropriate paragon path and/or have a magic item that will make up the difference." So if you're trained in a skill you have a strong stat for, you've moved from being defined as "good" to "better off than you would be if you were untrained." Or at least that's how it feels to me.
Of course, this complaint's pretty minor; I can just go ahead and use the DMG2 DCs instead of the Essentials-era DCs. If a skill optimizer player were to emerge, I'd probably just start introducing "excruciating" difficulty tasks that get even better results than "hard" in order to challenge them instead of shifting the goalposts for the entire group. Might work, might not: but my most regular closest-to-optimization guy at the moment plays a goliath bard, and I'd rather not adapt the campaign so that he should reroll as an eladrin if he wants to keep making hard Arcana checks on a regular basis.
Personally I don't agree that the feats which allow you to move on to being 'best the world has ever seen' at something are boring.
I freely admit this disagreement is likely at the heart of the matter.
Yes, they are static bonuses, but they feed into and reinforce what you want to do. In any case PCs get plenty of new toys regardless of what you do with feats. You get powers and then PP features etc at virtually every level. Especially once you hit paragon there's really not that much need to add a new gewgaw to your character with every feat.
Well, we're just getting to mid-paragon right now, but I can tell you right now that the three choices that are appealing most to me (and I can think of about six others on top of that) are
(a) Clever Tail [adds a new trick]
(b) Agile Athlete [makes attempting combat stunts more feasible and appealing]
(c) a math feat like Paragon Defenses or an Expertise feat.
The only thing that makes me consider (c) is the gnawing sense of obligation to the math. I'm just not fond of that as a motivation to pick something for my character; it doesn't reflect any of the choices the character would make, it just reflects a metagame necessity. And when I tell myself "(a) or (b) would accurately reflect the character's actions and interests, but I should pick (c) to account for monster scaling," it feels kind of like something's gone wrong.
In fact honestly IME it isn't necessarily desired. As one of my players expressed the other day, her character has enough fiddly bits and it is welcomed to have an option to just say beef up some defenses and not have to worry about them anymore and not have some new thing to have to remember. PCs are going to have what, 17 feats overall? Plenty of room for some interesting choices even if a few MAY be more mundane.
It isn't necessarily desired, but yeah, that depends on the player. Locally, it's pretty desired. My wife's more prone to say "there are just too many cool feats and not enough slots." And even if you might have 17 feats at 30th level, the ones you take latest are the ones you'll use the least. It's one more incentive (for our group's playstyle, of course) to focus first on the ones that add interesting capabilities and reflect the character's personality.