I get that the show's a bit camp, especially now that technology has advanced by leaps and bounds to make B5's then-groundbreaking CGI work really show its age. But yours isn't a fair or accurate description of its qualities. In particular, I'm not sure how you can support a claim that B5 is less "cerebral and subtle" than TNG, a show whose writers never met a clumsy, ham-fisted moral browbeating they didn't like - DS9 has more to recommend it in that regard, I agree - but compared to a show with five-year-long plot arcs, with events in the first few episodes literally paying off years later, and with influences and references drawn from a range broad enough to encompass Tolkien, World War I, Bester, philosophy and political theory from Hume and Locke to Nietzsche and Carlyle, Jewish mysticism, Christian theology, Olaf Stapledon, A Canticle for Leibowitz, and that's just off the top of my head...honestly, where are you getting this?
That would be down to the three-caste system (warrior, worker, religious).
Personally I didn't have an issue with the way even the religious caste were portrayed - peace-loving but fearsome when wronged.
_Spoilers_
I mean, the entire Human-Minbari war was down to a misinterpretation (about open gun ports) - and revenge, of course. The fact that Delenn was religious caste makes her initiation of the war even more poignant.