Adhesive technology is advancing rapidly and certainly has its place. This does not mean it is a substitute for all welding applications.
Much depends on the design / intended use of a given structure. As used in aviation, the structure and parts are designed to be built using adhesive. Thus, the joint will have large surfaces in contact to allow the adhesive to create a bond over a large area. The cumulative strength is proportional to the unit area. Also the direction that forces applied to the structure act in is important. In a straight pull situation adhesives can be quite strong, introduce twisting movements or shock and they can fail much easier, depending on the adhesive. Bonding edge to edge is not advised with adhesive as there is too little surface area.
Yes, the auto industry is increasingly using adhesives and are designing many parts accordingly. However, many of those adhesive products will not be found on the shelf at your local auto body supply shop. They have a very limited shelf life (days or weeks from manufacture) and are therefore not generally available to the wider public. You can buy some really amazing adhesives but just as most shops will not have access to robotic laser welders, most will not have access to the stuff used in the factory. None of the auto manufacturers have abandoned welding quite yet.
I see an increasing number of uses for adhesives. At least for today, on things like mild steel quarter panels, there is still nothing better than a professional TIG weld. Crappy welding is another story but that is not the fault of the technology.
Alternate opinions are always welcomed!
BTW, Glad to hear Daves news that smoking is safe. I guess I should take up the habit!