Every planner hates monorail by default, but can never articulate what, exactly is wrong with monorails. I imagine my exasperation with this is not unlike your exasperation with BRT opposition.
I wouldn't make the claims that monorail partisans do that it can somehow be "profitable" in ways other transportation modes cannot. However, it's demonstrated that it's at least cost-comparable with LRT and provides higher levels of service. And the public, moreso than the planning community, is predisposed to like monorail. What's wrong with that?
Having said that, we're all shaped by our own experience, so I should confess that my view of the potential usefulness of monorails is probably shaped by my experience around the Seattle Monorail Project (1996-2005), the only voter-approved effort North America has seen to develop monorail as a high-capacity rapid transit mode rather than as a circulator or fun-ride. The project failed after consuming a decade of advocates' sweat and tears, because (a) its costs kept escalating and (b) its all-elevated profile was unacceptable to many people who care about the urban landscape. Another factor (c) may have been that the monorail's