I just thought of the alternative that you seem to advocate, and would give it a playtest, except the outcome is obvious.
The alternative to having healing surges, of course, being not having healing surges. My theoretical playtest with each character having 0 healing surges would inevitably lead to 1 encounter and then an extended rest (assuming they survived the encounter and the only non-magical way to restore HP is by taking extended rests).
What you've actually done here is demonstrate the problem with healing surges in D&D4: Whatever arbitrary value you set the number of healing surges per day at, you've created a hard limit beyond which adventuring is not possible because healing is no longer possible*. You've set the value at 0. D&D4 sets the value slightly higher.
(*Hussar's Literalist Disclaimer: Some alternatives do not exist, but not enough to sustain the adventuring day in most circumstances.)
The actual alternative, of course, is to remove the hard limit. Rather than giving each character "0 healing surges", you give each character "infinite healing surges". The mandated length of the adventuring day is now basically removed from the system.
Basically, there are two motivations for the 15-minute adventuring day: The carrot and the stick.
The carrot is stuff like the "nova strategy" where you burn through your most powerful abilities in an encounter and then immediately rest so that you can use those powerful abilities again in the next encounter. This existed in pre-4E. And, of course, it still exists in 4E in the form of daily powers and daily uses.
The stick is generally "you have to stop and rest or you'll die". 4E arguably weakened the stick by including encounter powers so that groups never "run out of spells". But the hard limits on the number of healing surges each character has essentially rendered that irrelevant by introducing a bigger stick than any pre-4E version of the game.
(Pre-4E versions, of course, had the same "0 hp and no healing left" threshold. But the amount of healing a party had access to was incredibly variable and completely trivial to adjust on-the-fly by DMs and, in many cases, the players.)
But this fragmentation would have happened anyways under the OGL as the modified rules grew farther and farther apart.
Possibly. But I would point out that Pathfinder wasn't the first time somebody published "alternative PHBs" or "alternative PHBs with a handful of minor rules fixes". It had been tried several times -- including by major publishers like Malhavoc and Mongoose -- and it didn't significantly fracture the playing base any more than the 20+ years of non-D&D core rulebooks pre-OGL had fractured the playing base.
Did Pathfinder succeed where the others had failed because Paizo did such a great job on it?
Maybe.
But it's far more likely that Pathfinder succeeded because WotC left a big, gaping vacuum of traditional D&D gameplay that Paizo was able to fill.
Notably, the 3.0 -> 3.5 transition didn't leave that kind of vacuum. (There was at least one non-WotC 3.0-compatible PHBs on the market when that transition happened. Their sales did not explode. Instead, they collapsed.)
It was only when WotC abandoned traditional D&D gameplay entirely in order to market a different fantasy roleplaying game under the same trademark that someone could do what Paizo did. Up until that point, the entire gravity of the OGL movement was drawn to the D&D core rulebooks. Oh, sure, some people successfully set up some orbiting space stations. In time there might have been some small moons. But it all funneled straight back to D&D.
Honestly, I'm not fond of Monte's organization. In particular, I detest moving all the stat blocks to a key'd list at the end of the module.I thought Monte Cook's work in Ptolus was as good as a 3E-ish product could be organized...
I think you're ascribing something to Cook which isn't Cook's.
AFAICT, no Malhavoc product ever moved all the stat blocks to the back of the book. Ptolus, Banewarrens, and Night of Dissolution all have stat blocks incorporated into the main text. This also applies to the Arcana Unearthed modules I own and Demon God's Fane.
So when Cook was actually in complete control of how his manuscripts were being written and formatted, he never used that format. It was only when he was working for other companies that you see the "stick 'em in an appendix" method.
And Ptolus really is the best organized RPG product ever published.