I've done quite a few wilderness expeditions lasting up to 3 weeks. You couldn't bring enough bottled water with you. Sometimes I was filter-pumping water from clear streams, other times we had to remove solids from muddy water, boil it, let it settle, filter it, then bleach it.
Self-dosed chlorinated water isn’t the worst option, but I wouldn’t call alternatives a luxury. Only people I’m familiar with that still use that technique frequently are PCT through-hikers, who are pretty desperate to cut any weight possible.
I think we need to draw a distinction between "normal" and "abnormal". What is "normal" for thru-hikers is off-the-charts privation for most people (source: am an AT thru-hiker GA->ME '10).
Under the sorts of circumstances where most people would seriously consider using bleach to render water safe to drink (i.e. highly abnormal ones), bottled water is a luxury. Bleach allows us to meet a biological need starting with water people in the developed world would consider unsafe for drinking.
Bottled water meets the same biological need at greatly increased distribution and packaging costs; that makes it a luxury. Under normal circumstances, there's sufficient capacity in our logistical systems that we don't see those costs. Under abnormal circumstances, bottled water rightly should be one of the first things to be shed from the supply chain given available water that can be made potable with bleach.
On a thru-hike the last link in the supply chain is your back, and as the GP points out there much more important things to carry than bottled water given the ability to purify water found along the way.
As an aside, most of us don't use bleach. Polar Pure has long been my favorite (it's cheap and extremely robust), AquaMira is extremely popular (at higher cost per liter), filters are quite popular on the PCT, particularly the Sawyer Squeeze, and UV solutions (Steripen) also have their adherents. Basically nobody uses Potable Aqua. I'm not even sure why they still make that stuff; clearly it sells.
Thank you. This is exactly me point. Bottled water is one of the things that should be shed from the supply chain during emergency situations for precisely the reasons you have given.
I've done quite a few wilderness expeditions lasting up to 3 weeks. You couldn't bring enough bottled water with you. Sometimes I was filter-pumping water from clear streams, other times we had to remove solids from muddy water, boil it, let it settle, filter it, then bleach it.