Drop the word sport from the name? So what, just call it "E-"?
They're not trying to make it out to be a traditional physical sport by calling it "e-sports", it's just that it's the most appealing name for it. Something like "e-competition" just doesn't have the same ring to it, you know?
Besides, the "e-" part of the name already counteracts the typical physical expectation one expects from just plain "sports". If, hypothetically speaking, they called it "Virtual Sports", would you still take issue with the fact that it's not physical despite the fact that the name clearly tells you that it's virtual and not physical? Do you take issue with Madden and Fifa being called "sports" games?
Just think of "e-sports" as being something totally different from just plain old "sports" rather than some subcategory, and be glad they don't call e-sports competitors "athletes".
Anyway, on the topic of Rocket League... the Switch port seems pretty impressive from what I've seen of it. I've heard a lot of negativity about the graphics, but what I've seen looked very acceptable. The crossplay with Xbox/PC is also very cool... for some reason the pessimist in me just kinda assumed that'd be something patched in later, so to see it working pretty much flawlessly out of the box on day one is very nice indeed.