I think that there are two different issues being commented upon in this thread.
The first issue is about the actual weight of the load carried. Which brings up the question: Why spend time looking at the weight going into a backpack?
Let me start by stating that it is pointless to argue that people CANNOT carry a lot of weight. The fact is, folks in generally good health can carry fairly heavy loads if they choose to do so.
It is equally pointless to argue against the fact that it is far more enjoyable to carry less weight, than it is to carry more. Aside from the aspects of enjoyment, there are some great reasons why one should carry the lightest backpack load available to themselves.
1. There are correlations seen regarding the frequency of specific types of injuries and strains, including blisters, tendonitis, shin splints, ankle injuries, etc, as weight loads increase. That does NOT mean that everyone who carries a heavy backpack will suffer such occurrences; only that the chances of such things happening go up.
2. The reason Ray Jardin and other backpackers evolved the world of backpacking into the direction of the lightweight and ultra-lightweight backpacking movements PRIOR to the existence of today's high tech gear and clothing, is precisely because of the fact that it is far more enjoyable to carry less rather than more.
The lighter the weight carried, the less energy it takes to reach one's destination for the day. Aches and pains are lessened. At the end of the day, the amount of time it takes to recuperate and then go out to enjoy the surroundings is shorter.
How much weight is carried in a backpack
does matter. I very much disagree with a notion which implies that carrying of 20 or 25 pounds uphill and downhill is
not more noticeable than is carrying 11 or 15 pounds. . . . that the 11 or 15 pounds is not far easier and more pleasant to carry.
The second issue in this thread: Focusing on backpack weight to such an extent that it causes anxiety and worry. Yikes!!!
While the amount of weight does matter,
obsessing over weight for a Camino, as opposed to simply being discerning about choices, is silly and pointless.
On Camino, if someone becomes tired and frustrated with hauling too much weight, and s/he finally figures out they don't need a 5 pound sleeping bag in July, stuff can always be mailed home or ahead. Unlike being in the middle of a wilderness backpacking trip, you are not stuck with having no other recourse but to live with the decisions made while still at home.
So do not develop ulcers and worry lines over your backpack's weight.
A sort of connected issue is about the role of the experienced members of the Forum in relating information to the inexperienced about such things as equipment choices. There are a lot of wonderful and experienced members who can offer excellent advice. Threads, like this one here, are thick with viewpoints and practical information. Sometimes, but with exceedingly less frequency than I would have imagined, those viewpoints and tips might seem to conflict. But is that something to be concerned about, as I've heard made mention?
I would be disappointed if there was a singular, homogenized viewpoint. The level of experience and knowledge on this Forum is fathoms deep, and it comes from proven and practical implementation and use. If I post something like an equipment list, I do it as an example of a possible choice; sometimes I have related the 'why' of those choices. I do so with a viewpoint of a long-distance backpacker.
Someone else might offer similar advice, but with different practical choices. Such a viewpoint may come from experiencing the practical logistics available while walking on Camino; logistics which are very different from wilderness backpacking.
These different viewpoints are oftentimes complimentary. If viewpoints seem in conflict, like choosing heavier boots as footwear as opposed to trail runners, it is often based on personal bias, comfort, and preference . . . and this includes the fact that changing a method, or a piece of gear or clothing, can be 'mentally' uncomfortable.
Not liking change can be a very valid reason for making a choice.
Geez, that was long-winded. For those that read this entire post, you have great tenacity