Bob - thanks, I agree with you 100% of course. However that was not what my point was.
I was merely pointing out that, while your focus is rightly on safety, it is likewise unfair to generalize that (a) everyone at the dealership is somehow more skilled and knowledgeable, and (b) DIYers are not competent at handling these types of issues.
My post spoke to the first case. As for the second - some of us might not be paid technicians, but might nevertheless be otherwise competent at handling such a scenario.
I choose to go to the dealership when it is a warranty issue (now I am rethinking even that) or when the issue overwhelms the limits of my knowledge. The trick with the latter is knowing when to ask for help.
Regarding my oven - the most frustrating things were the clear lack of quality in the manufacture of the appliance at the outset, and the incompetence of the technician in the attempt to effect the repair. Don't ask me how I know but I could have done a better job myself.
We are on the same page.