American Heritage Dictionary of the English Language, 5th Edition:
coherent
1. Sticking together; cohering
2. Marked by an orderly, logical, and aesthetically consistent relation of parts.
incoherent
1. Lacking cohesion, connection, or harmony; not coherent.
2. Unable to think or express one's thoughts in a clear or orderly manner.
The reviewers of White object to 'incoherent' by stating it has ONLY meaning 2 above, and are oblivious to meaning 1. As to "multiple principles, relationships, or interests" I'm not sure what you mean by that. I think coherent definition #2 above talks about "aesthetically consistent relation of parts." It isn't a question of multiplicity, it is a question of aesthetic consistency and thus things 'sticking together' and possessing 'cohesion, connection, or harmony' (or the lack thereof). So I think what RE means by 'incoherent' is literally that, but the reviewers took the meaning #2 of incoherent and assumed that was the only possible reading he could have meant, and thus objected to the term on the basis of claiming it implies that a lack of adherence to a single GNS agenda literally implies that the game participants will be unable to express themselves clearly.
It simply appeared to be a rather narrow and ill-considered criticism by the podcasters. Lets give them the benefit of the doubt, you often stumble a bit when speaking live.
See above... this was simply the first dictionary definition that popped up for each word in a DuckDuckGo search. It is a commonly used and perfectly cromulent dictionary AFAIK (not being some great expert on such).
Yeah, I'd be interested to know if there is some great degree of divergence of opinion on these words. I mean, I certainly agree that people use 'incoherent' to mean "someone said something to me and it was impossible to understand." but that seems at best a specific variation of a secondary meaning of the word.
Well, hmmmmmm. I think games could legitimately 'just happen to be coherent' and that's fine. In fact the original D&D game is pretty darn coherent! Especially in its more realized B/X form, where it is QUITE clear what the object of the game is, and AFAICT all of its mechanics and advice are pretty focused on that. However, lets give the authors some credit, while they may not have thought in terms of specific ends WRT agenda, they were certainly conscious designers with specific goals.
I think it is fair to say that most games which are designed fairly naively will most likely exhibit some lack of coherence of design. Even when substantial intent exists, without a framework which can describe play in a way which allows a thorough analysis of agenda it is hard to 'get it right'. I mean, 2e is a beautiful example of a game that is VERY incoherent. OTOH in terms of how it was actually played by most people it probably worked fine, 90% of the time. I know it failed spectacularly for me in one instance (after which I never ran it again) but I think most people just ran modules or whatnot and assumed that the rough parts were just the cost of playing RPGs generally.