blast off on a flight crossing controlled airspace without submitting a flight plan is going to cause increased workload for the controller.
With the greatest of respect to yourself and that comment, that’s their job! To deny a clearance because it increases workload due to no plan is pretty poor.
Each time I get issued a slowdown, holding pattern, metron ground delay, visual approach as #2 etc etc all increase my workload too. Doesn’t mean we don’t do it.