Cheaper launch system means you can afford more missions, or do the same missions for less money. A smaller budget probably means less risk of Congress cutting your funding.
On the other hand, the space shuttle was the coolest thing imaginable in the 80s. It was crazy that it could launch like a rocket and land like an airplane.
My opinion now is that it was an unnecessarily complex, highly inefficient launch system.
The issue that I have is that there should have been no requirement to carry cargo on the shuttle. Launch cargo on big dumb rockets, and launch and return people using a fancy space plane. The space plane would be smaller and likely not need booster rockets.