Is a mechanic that causes you to break immersion and laugh out loud in an otherwise serious game situation a problem?
No. Because there's no such thing as a mechanic that /causes/ you to break immersion. Mechanics are abstract, no mechanic can pull you in and 'immerse' you (even VR to the extreme of a ST:TNG holodeck probably couldn't do that), immersion is a choice players make. If you can't keep from laughing during a serious moment in a game - whether it's a mechanic that doesn't fit what it's modeling well enough in your eyes, or a player whose RPing a character that he's a radically bad physical 'fit' for, or a plot whole the DM has left open, or an un-intended pop culture reference that accidentally slips into the dialogue - then you just weren't quite up to the challenge of intense RP at that moment.
Of course if that mechanic does not affect you that way then it's not a problem. It was a reguar occurance for my group in 4e. We finally decided we can't tell stories with this game and take them seriously at all.
I guess it must just be a straw-that-broke-the-camel's-back thing for you guys, then. Because the suspensions of disbelief required to get from guys sitting around a table rolling plastic dice, to heroes fighting dragons seems like it'd be orders of magnitude beyond that last little bit of suspending dis-belief because of a 'plot coupon.'
Essentials was a variation on an edition that people had already stopped playing.
And 5e will be a new edition of a game that people had already stopped playing. In both cases, the idea was to address the issues voiced by those how hated it in an attempt to get them back. Essentials failed miserably, and tanked worse than ever. 5e thus has even more people to try to win back.
For that matter, 4e tried to 'fix' the problems people complained about, and, while it's failure may have had more to do with timing, presentation, or the GSL, it's clear that just trying to cater to the squeakiest internet wheel is not a formula for success, by itself.
Well I don't believe balance per se is something anyone is against. But if you are right in your thinking that achieving balance requires plot couponish design then I'd say a lot of people are against it.
Balance doesn't require dailies, it just requires that different classes not have substantially different proportions of their effectiveness in the form of daily resources. A 'plot coupon,' intended as such by design, is a strong narrative device, particularly good for encouraging the 'co-operative storytelling' aspect of RPGs, but such a mechanic could promote balance or imbalance depending upon how it was implemented. Daily powers, regardless of rationale, have never proven great for balance in D&D - even if they don't cause class imbalance (if all classes have them, for instance), they still cause encounter imbalances if the DM doesn't stick to an average number of daily-resource-consuming challenges per day.
So, I certainly don't want to come down on the side of dailies being a must-have in 5e. I'd be delighted if they were relegated to some module, or if a more flexible implementation of limited-use abilities were given, instead. Something adjustable by the DM to fit the pacing of his campaign, like the 'dials' in Fuzion, for instance.
There is no functional difference between someone arguing zealously and uncompromisingly against every mechanism that has succeeded in delivering balance on the basis of a grab-bag of rationales, and one arguing against those same mechanism for sheer dislike of balance, itself. Both want the same thing.