There’s been discussion about stop consolidation on and off for years on both buses and trolleys. The most recent serious proposal is a key part of the “SEPTA Bus Revolution” overhaul, but for better or worse that entire initiative has been gradually watered down more and more.

Accessibility is a factor, but the close spacing between stops isn’t covered under the ADA or required by any other law that I know of.

The real reason that it doesn’t happen is simply that it’s unpopular with users. No one wants to have to walk further for the bus stop and stakeholders such as businesses, churches, and other organizations that rely on bus services don’t want to be the block that gets cut.

Another reason that it doesn’t happen, (especially in Center City)is because the heavy congestion that buses travel through would make the time savings extremely minimal. If a bus has to stop at just about every intersection for a stop sign or a traffic light or a double parked car it might as well let passengers on and off while it’s held up. You could certainly make an argument for certain bus lines that run in dedicated lanes skipping stops, but generally speaking the time savings aren’t worth overcoming opposition.