Yeah, this is how I feel. I like to have both options. Actually, whilst I know this bothers some SP game supports, I do think SP games can have a really good, thorough SP experience and still deliver solid MP experience as well, whether it be integrated in the SP mode or totally separated. There's been a wealth of games this gen that did nail this concept down (Uncharted, LBP, Assassin's Creed 2+, Demon's Souls/Dark Souls and there's some more than I believe could still do this very well and could be a win for everyone.
I'd love for the next Batman game to have elements of multi-player as well, like a full fledge SP experience as the usual main game (and not at all neutered or slighted any) and then have challenge rooms or some 2-4 player separate campaigns modelled in teh same vein as the SP game, but not just a tacked on experience. I think if done right, it could be absolutely awesome.