There is one big argument against replacing the stunt show with the ride: Cost. But other than that, the ride is the better business choice.
Consider:
The Stunt Show has a big cast, most of whom make a higher pay grade than the average attractions CM. Not to mention the extra liability involved in the stunts. Possibly the ride maintenance budget is higher than the show's, but not by much.
Rides have higher repeat value, due to the fact that audiences feel like more of a participant if they are moving through something and having things happen to them, rather than sitting on their butts watching something happen to others.
The Indy Theater holds about 2000 people per show. The Indy Ride moves about 2400 an hour. The ride clearly has a capacity advantage, even more so when you consider only about 5 stunt shows are performed daily (if that).
A continuously running ride that does not require highly skilled entertainment performers can keep people in the parks after dark. Almost all of the Studio's shows are done by 5:00. Having more things to do at night keeps people on property (i.e. spending money).
A continuously moving ride eliminates the famine/flood problem. Every time a Stunt Show lets out, 2000 people descend into the park, flooding the other lines.
The merchandising opportunities are greater for a ride. The "I Survived" t-shirts, the on-board photos, etc.
You already have 2 versions of the ride to pick from (Disneyland's and Tokyo's), so your design costs are minimal. It's basically just the construction cost.
You do lose space for events like the cheerleading competition and such, but just move them to WWoS.
You already have another stunt show in the park (albeit car-related).