My experience differs from yours.
Does it, or did we just look at the experiences along different lines? I sliced it by newbie/lapsed, you went by analytical/creative. We looked at different things, too. I didn't even mention dailies vs at wills, just 'fighter powers.' You didn't mention surges or how CON affects hps. (every veteran gamer I've seen roll up his first 4e character got the hps wrong, or at least had a moment where he questioned "CON? or CON /bonus/?" - myself included).
As I break down what you posted along newbie/vet (not lapsed, BTW?), I see:
You had 4 vets and 2 newbs.
Two vets had no problem with powers - but were playing spellcasters. A third specifically played a swordmage because he balked at a fighter with dailies. The fourth (and the 'creative' paragraph is very hard to parse, you specify 3 players, but mention at least 4 classes they played initially), aparently the Paladin player, though, having 'no problem' with Dailies, didn't use them as a paladin (a class that has always had some spells in spite of being fighter-like), then switched to rogue and exclusively used at-wills. That's not really inconsistent with the experiences I've had with lapsed or ongoing players. They have no problem with powers when playing casters, but some when martial powers come up.
You don't mention whether the last player was a lapsed or new gamer.
While I'm sure our subjective experiences were different, I'm not so certain the phenomena we were observing were /that/ different.
Some players just like going outside the box. It doesn't mean they're dumb - just that their brains work differently.
So give them a smaller box? Thus more opportunity, and impetus, to go outside it.
That's not snark, I mean it. I have seen the phenomenon where a player will get sufficiently caught up in the options on his power cards that he'll forget he can do things not on them.
There are other systems - effects-based or downright freeform - that /really/ encourage or support that style, too. In a game like Ars Magica (well, the version I vaguely remember), for instance, there are hardly 'inside the box' spells to use, at all, you have to work up what you're trying to do with a spell when you cast it.