Yes, I agree. That's why I believe we are not going to loose the technology to fly (at least within this century), unlike many people in the peak oil scene.
However, you have to consider the economic feasibility, not just the technical one. If you follow news about airlines, you will recall that they have gone through a series of hardships, raw times and infighting between different groups of stakeholders (unions vs companies). You can write it off as random incidents, or you can understand it under the lens of increased costs and multiple competitors trying to get each a bigger slice of a shrinking pie.
I have seen during my lifetime how conditions for the passengers have deteriorated. I recall as a teenager or a young adult, boarding a plane was a wonderful experience. Now a days, they treat you like cattle, and I am not just talking about the hardships imposed by TSA screenings (though they take a fair share of the blame).
If you add two plus two, you will find that this decreased passenger comfort is tied to cost cutting measures. But why to cut costs if you can simply pass those cost to the customer and keep the quality of service up? I do not presume to know the answer, but my intuition tell me that the leadership at airline companies have run the numbers and figured out that there is some sort of inflection point in the demand curve, and an increase in prices would cause a severe drop in usage.
Instead, a less bad alternative is to cut cost, punish quality, and face a small decrease in demand, but as long as the margin remains in the black the company can keep operating, and wait for better days. My fear comes mostly for the moment when airlines run out of comforts, and begin cutting cost in critical areas of operations such as plain maintenance. Even a modest number of non-fatal incidents may shift perceptions of safety and make the bottom of the bucket fall from under the demand pool.
Now that I think about it, this is a market ripe for disruption.