I am not so sure it is the general public taht is so hard to convince. When they come out to view and implosion I think they expect there to be a dust cloud. I think in a lot of cases they would be disappointed if there wasn't one.
I think it is going to be more increasingly a problem with the regulators especially with the new revisions to the AAQS. Under the proposed new regs, any release of fugitive emissions from a project site is a fineable offense. The fines increase with the number of infractions. So if you shoot a dusty building in Podunk, Iowa and the there are visible emissions you will be fined and if you do another project in Miami, Florida the next day the fine increases and so on and so on. It's sort of similiar to the NJ DOL regulations for air overpressure.
This has the potential to affect conventional demolition projects too.

Implosions only concentrate the dust for an incidental duration. What people don't undersatand is that conventional means deploy the dust in an unmitigated environment. Air samples have shown lesser daily emissions for conventional demo work but overall emissions exceed that of explosives demolition work.