Many of us know that Steve Ditko doesn't get as much recognition as he should for co-creating various Marvel characters and that he has been a recluse for decades. If I was in his position, I certainly would want to do some interviews to express my views on not getting the fame/royalties I was due. It is possible to balance respecting another's privacy and get an interview. For example, a journalist could simply ask Ditko about question not getting the fame/royalties he was due and the interviewer would be on their way. Also, I think it is possible to be overly protective of one's privacy.
Would you consider Steve Ditko flat-out refusing to give any interviews to rude?
Let's not forget that outside of the above, there could be a case of where the interviewer had a difficult time in their life (like depression or a history of being abused). As such, that interviewer may say that it was Steve's work on [title] that helped them persevere. Also, there is a Ben Kaye 6/28/15 CBR article called "An 8-year-old fan wrote Steve Ditko a letter, and here’s how Ditko responded". If I was Steve, I would feel humbled that a young kid was a fan of my work from the 60s. That should be more special than not getting the fame I was due.