You really have no idea how most projects are run, I work on projects that can run for years, and in the billions of dollars at times and resources are not an unlimited thing, you may have long lead times, you may run into technical issues after things are implemented and countless other factors. No project is ever perfectly ran, Some may be ran under budget for various reasons and some on budget, but resources are by and far the biggest factor and if you need specialized people, and or have people sick out or cant find enough resources you will almost always run into some issue of people working over time the course of a project. Its dumb to say the project management sucks, because it's rare you dont have to have people working OT etc for various reasons.
If its sustained OT over months and months thats bad project management, if its OT for a week or two here or there to pick up certain resourcing issues beyond your control and for certain resources that typical in a project. Esp when we are talking for software projects where you constantly see studios outsourcing when they can, trying to find contract work in a market that is frankly highly competitive.