Well, how many encounters should an average party be able to take on before running out of resources? 1, 4, 16, 64? How many encounters would it take for you to not feel like '15 minutes'?
I don't think this was ever the issue. Rather, it is how 4e supposedly claimed that PCs would not be limited to the 15-minute workday, yet the number of encounters they can handle each day seems no less limiting than in 3e. In fact, 4e seems much more unforgiving in terms of how far you can continue to push yourself after your resources have been exhausted.
I admit that at 1st lv, a typical 3e party is much more fragile than a 4e party (for example, a 3e fighter has just 12hp, and an orc barb easily deals that much damage with a single blow). Past 3rd-5th lv, I felt that my 3e party could readily handle at least 4 encounters each day. It was not impossible to construct a party with nigh-infinite resources (binder, warlock/dragonfire adept, warblade, factotum) which could theoretically just go on adventuring forever without needing to stop to replenish their resources ever.
In 3e, players had ready access to healing, such wands of CLW/vigor, binder5 with improved binding for buer etc, but people seemed to take offense to relying so extensively on magic gear.
In 4e, each player was more or less self-sufficient in terms of healing, albeit more limited in how readily they could access healing past a certain threshold.
This makes me wonder if it is really such a big deal as to how or where healing comes from.
