Coaldemon, I have read some stupid posts over the years, and yours is right up there. Aviation operations are dynamic. HR is in an office. If the CP is called out there will be someone else able to be called in to fill the interview seat. If there is a cancellation by all means offer an opportunity at short notice to candidates on the chance they may be 'on the spot'. For scheduled interviews, keep with the program. Large operators with dedicated HR have no excuses jerking applicants around, and if they do they have lost their integrity from the beginning and should be avoided if possible.
Furthermore, you seem to be pushing the bar lower in your post, would it hurt to set your expectations higher?