Full disclosure, I am not a biologist, a fisheries management specialist nor did I stay in a holiday inn express last night.
Typically lakes and reservoirs that have aquatic vegetation carry more pounds of bass per acre that lakes and reservoirs that do not have aquatic vegetation.
I believe part of the reason fisheries management types do not like hydrilla is that it can make it difficult for shore bound anglers to fish. The near shore shallow water can get choked out. Shore anglers complain.
Hydrilla up here in Maryland is generally a good thing in lakes and reservoirs that have significant open deep water where hydrilla can not grow. The lake can not get completely choked out. We also have the cold water period where the hydrilla gets completely knocked back every season.