I do think that drinks with proper electrolyte replacement are helpful.  I agree though that they have become big business.  To my way of thinking, the main problem with Gatorade is that it's far too sweet.  I wish they'd get 80% of the sugar out of that stuff.  I'm still looking for a reasonable electrolyte drink that has proper sodium and potassium levels, and much lower sugar.  
Yeah - I do know about ORS.  It works but tastes lousy  :-)
There has to be a compromise somewhere.
By the way ... the joke I tell people is this.  Drink one Coca-Cola.  Then drink one Pepsi.  The Coke uses sodium-based chemicals.  The Pepsi uses potassium-based equivalents.  So if you drink one of both - you've got your sodium and potassium, right?? hahahaha!
Pete2 
compare the ingredient labels for any electrolyte beverage with that of a v8 juice can. V8 is better, cheaper, and provides 2 servings of vegetables, rather than a batch of empty calories. The cans are arguably more recycle-worthy than the plastic containers. electrolyte/bottled water/soft drinks are a triumph of marketing creating a perceived need and selling a product to fill the need. Eating a balanced diet eliminates the need for supplements.