This non event is a typical example and my questions to you easily lead you into the trap of looking defensive and secretive; I know full well what a plug type door is, but my question about the failure mode was not unreasonable and the DC10 incident will be remembered by many.
Except, that I answered your question before you repeated it. I also referenced you to the official accident document reports of the time. The answers were therefore qualified and reasonable. If you think I fell into "the trap," then well done. I think the repeated use of the term "confirm" rather gave away the fact you wanted a particular answer, more than an accurate or informed one. However, whilst I am happy, and it is reasonably easy to take the time to provide such qualified responses on a forum like this one, it is virtually impossible to do so in the practical confines of the pre-flight period in dispatching a commercial airliner. For this reason as much as any other, the information that is given over the public address system, needs to be considered, measured and delivered in a professional and tailored manner at all times.
An airline pilot has a library of information at his disposal concerning the dispatch legality, advisability, operating restrictions, and recommendations for any given deviation, fault or unservicebility. In addition he has the luxury of specific training and experience to fall back on as an additional benefit to the application. On top of this he has the resources of his company engineering and operations departments to communicate with for advice, opinion or comment, if and when required. In other words there is a great deal of resource for a highly trained and experienced professional to utilize as part of the decision process. Attempting to communicate what is often a complex process to passengers who for the most part will obviously require a relevant and simple explanation of matters that need concern them, is clearly another matter. The failure modes of cargo doors is not a part of that repertoire, any more than the fact that yesterdays engine change didn't involve the use of a fork lift truck, the runway has just been checked for fallen debris, there are thunderstorms on our planned route, or we are using a more marginal method of calculating dispatch fuel requirements, because of performance limitations.
It isn't a case of being secretive. It is a case of confining complicated and easily misunderstood processes to those with a professional need to know, and ensuring that the information given to the customers is in a format that is properly reassuring, honest, and relevant to their safety and comfort. That takes a little more thought than it might superficially appear to.