I think I see what you mean - something like "oh bother, this music I'm hearing is really not very interesting, but then it is so very middle-of-the-road so what did I expect?" - that is to say the uninterestingness being at a higher level of awareness than the middle-of-the-roadness. Fair enough.

By "work", in the BBCSO's terms, I meant "will sit reasonably easily in a mixed orchestral programme/not antagonise the players/not require masses of rehearsal/will be taken notice of favourably by critics", etc. (did I forget something?), as opposed to "might expand the orchestral repertoire in an interesting and perhaps provocative way, which might encourage the audience to think about the orchestra in some way differently".

I've come to the conclusion, by the way, that my own recentest essay in this area didn't go as far in that direction as I was hoping it would, which isn't to say I'm disowning it or anything, I'll be making a few small changes as and when necessary but nothing massive - in the process of trying to go to some concept of "first principles" in orchestral writing I think I ended up finding something familiar rather than something unfamiliar (put like that it seems obvious of course). Next time a different line of approach will have to be worked out. But I have a couple of years to think about that.