How is that odd - the whole point of interviews, and especially on-site ones, is to decide whether or not someone is 1) qualified to do the job, and 2) a good fit for the role/team/company.
I think that any candidate who is not "qualified" for a job would either have the qualifications on their CV or not. You might say that the candidate hasn't got the right experience or hasn't demonstrated the capabilities required - but "not qualified" doesn't make sense for a mature organisation interviewing candidates. If it was followed with " and we have sacked the bozos who invited you for an interview. I'm really sorry for wasting your time. Best..." then fair enough.
Everything is relative. At a company, I was a top dog, by an order of magnitude (if such things can be quantified) at developing software in my field. I thought I was pretty damn good at it, and put something to that effect on my resume.
Later on, I applied to a different company, and while I got hired...holy shit. I have one hell of an imposer syndrome, because an "average" dev there can seriously show me a trick or two...or a hundred. The top of the food chains might as well be gods among mortals in my view.
So really, a resume only tells you what the applicant THINKS their qualifications are. Nothing more.
3. You got the interviews, lots of people didn't. That's a pat on the back there.
4. There are lots of other companies.
5. Focus on your strengths. Keep going, push on, and you can come back to these companies in a year or less with much more strength and steel than now.
