OLG, that is the "key", the programs do indeed have to be carefully selected so that they are well matched to the interests of the audience. I think it would be possible to do this, provided the activity was properly directed and adequately described, so that folks attending it had a very good understanding of the intent and scope of the presentations, and the presenters had a clear understanding of the goal as well.
Properly prepared and adequately illustrated presentations can tackle technical subjects (even difficult ones) and still be interesting and entertaining, and there are people in the industry who do these type of presentations quite well.
In 40+ years of attending both industry and railroad enthusiast events, the most memorably "bad" and boring presentations I have ever seen were not about the technical aspects of locomotives. The all time winners, as I remember them, included a long and boring roster shot slide show sponsored by a historical society but directed toward the interests of model railroaders. It was an incredibly tedious exercise in rivet counting. Another was a talk by a retired railroad superintendent about the "good old days". The guy may have been a great superintendent but he was a very boring speaker. I also recall a "historical" presentation by a local college professor. That gentleman was completely lost, he had absolutely no clue whatsoever about subject matter of interest to railroad enthusiasts.
And discussion of locomotive technology does not necessarily have to deal with current production to be of interest. As we can see from this forum, there seems to be a lot of attention given to comparing features, advantages, and disadvantages of ALCO, EMD, and GE products produced in the past. Just look at all the interest this string has generated at a time of the year that is usually slow for participation in discussions.
"We Repair No Locomotive Before Its Time"