Not if your service is different - the Uber driver isn't a taxi driver, he's a private car driver. It's like saying people going to work at a gas plant are scabbing when coal miners are striking.
Yeah, that's pretty much what I'm getting at with my line of questioning.
If a person works in an industry that creates a substitute for the products or services of a unionized industry, is he or she a scab worker? Obviously, when the company hires temp replacements, that's very direct. But if a new industry makes an old industry irrelevant, using that kind of critical language seems like an unfair attack on the workers in the new industry.