Dear AR15Guy2009:
Crenulated surfaces, like those on the E2D, are low profile enough to fly under the radar. However, there are some attachments out there--and some off-the-shelf lights--that are obviously weapon oriented. Like anything else, if you give people a reason to consider flashlights a weapon, they'll start doing so. They'll also want to legislate them, restrict them, and do all the stupid stuff they do with guns and knives.
Like everything else, crenulation in moderation is fine...
Stay safe,
Mike