I don't think it is the make itself, it is the reputation of the make and maker, maybe coupled with the apparent quality of the gun. If Klotz guns are known for failing to fire, falling apart, or blowing up, I would not buy a Klotz. Or if Klotz guns look shoddy, are made of cheap materials, or show signs of careless manufacture, I would probably also not buy.
Maybe that is not an answer to your question, because I doubt I would "have an interest" in Klotz guns at any time.
Still, I have bought guns that failed both tests, solely for possible collector interest. For example, I am the proud(?) owner of both a Rogak and a Colt AA2000, both of which I bought because of their known problems, not in spite of them. If I were in a self defense situation, I would get one of them out - and give it to the bad guy.
Jim