I think people anticipated "transportation problems".
They didn't expect that the main highway running through the heart of the city would be closed entirely from 8 miles north of the city limits to 12 south of of the city limits on the other end (imagine NYC closing I-95 from White Plains to Newark! Nevah gonna happen.), that all airports within 35 miles of Boston would be closed except for regularly scheduled flights into Logan Apt, that the subway system and commuter trains would be stopped outside of the city, that major city streets would be blocked off for 10 blocks all around the convention site, that using boats on the rivers and in the harbor would be eliminated, that the water taxis would be out of service, etc... Of course, those are just the things we've been told about so far. They still have a month to decide to close up more things.
Let's see, that leaves walking in and bicycling. Of course if you do either you are subject to random searches and ID checks and you have to justify why you are there.
Yeah, you're right. I have ZERO faith in this thing.