Vitamin C is an acid, so is carbonated water. When you drink it it goes into your stomach, which is filled with more powerful acid.
Brake and carb cleaner are not acidic, they are volatile petroleum distillates. Great on grease and carbon build up, but the counter was sticky which doesn't sound like either of those, it might even be possible that it's liquid gasket residue which is usually petroleum resistant.
They are comparing two very different things and implying one is unsafe. It's the same thing when they say a food is bad because it uses an ingredient that is also used to make yoga mats. The ingredient could be perfectly safe but has properties that work well for both (hell, water is used in cooking AND the production of pesticide... ban it!)