[inapis]

IRCTC is infrequently buggy (no more than an average website). They might not have optimised for poor connections and thats where most people's buggy experience is.

It is generally fast except between 10am-12pm every day (i.e. when the tatkal systems open) and that is what frustrates most people. When called out on these issues, IRCTC has consistently refused to add capacity to deal with the demand between 10am-12pm. You are correct that this could be solved by using quotas and reservations but they haven't done that. My only guess is that it is for political/bureaucratic reasons. It's easier to blame capacity issues than tell the reality.

>reserved a certain proportion of the tickets for rural users

This already happens. There are quotas of different kinds.

P.S. You know what? You are actually right. There's no technical reason for this to be the way it is. They are using that explanation as a cover for a political or legal problem or by occam's razor, they probably have a fixed budget (and not allowed to use on-demand services like AWS) and the govt won't approve the budget necessary to solve the capacity issues between 10am-12pm.