There are always going to be competing interests and tradeoffs. Stopping the train is expensive, in terms of time. If one wants to be most accommodating for those with physical issues, then the cost of that is slower or less frequent trains.
Of course. But it's easy for many to unthinkingly look at public transit through the lens of efficiency for able-bodied riders and ignore those who are long-term or temporarily disabled in some manner.
That attitude is part of the reason why few people take public transit in most US cities. When the transit system is not optimized for the majority, the majority will not use it. That leads to a death spiral where it becomes just a safety net system for the people who have no alternatives.
