While I agree that the ideal procedure for a drifting diver is to deploy a SMB at the earliest opportunity, to expect all recreational divers to have the tools and necessary skills to safely deploy one is not realistic at this time.
This is not to imply that such procedures/tools/skills cannot become more widely instituted as an integral part of standard recreational diving practices. (Like the gradual integration of SPGs, BCDs, safe seconds, and etc.)
In Cozumel they managed to make it a requirement. Coincidentally, the first place I ever used an SMB from depth. I think you underestimate people. Boats could also provide SMB's and spools.
Several boats I've been on (FL East coast area) provide flags and even computers if the diver doesn't have one. I think they were "no extra charge" but I'm not 100% sure on that since I didn't need their stuff.