I think the system has potential for supers use, but that the superpowers selection (and attendent modifiers etc) needs expansion. In essence I feel that a setting incorporating the magic system(s) and psionics alongside powers can work. That said, I feel that the superpowers need to be a costlier way of building broader and/or more reliable effects than available through the restricted mechanisms of the other optional power systems.
It also occurs to me that there are options that can be used by PC's to restrict their own lethality - which is the point of many comic book stories, isn't it?
With great power comes great responsibility.
I think the perceived problem lies in that (relatively) low-lethality is the default mode for many super-hero rpgs such as DC Heroes/MEGS/Blood of Heroes, Hero/Champions, Mutants and Masterminds, so BRP suffers a little by comparison (as can GURPS for similar reasons).
Another issue is the 'why?' factor. Why does a GM want a system that plays more like another system? If it is perceived that the other system works more accurately or effectively (or both) then use it. But if there is something that is preferable about BRP by comparison, then the question arises of the need to bolt-on (more) rules changes to achieve the desired outcome, since the result will potentially be removed from the starting system - in other word that which is in favour of using one system gets lost amid add-ons.
I honestly think that the basics exist to run not just so-called 'gritty' stories, but also more 'mainstream' comic book inspired tales. Admittedly this view isn't supported by experience yet, but that is something I plan to address.
One thing that did occur to me is the potential to run games in a so-called 'widescreen' mileiu/style (like the Authority, the Ultimates, Black Summer et al).