~ It doesn't matter that while taking from Bitcoin they are also adding to it something as what they take exceeds what they give back
But what if what they take doesn't exceed what they add? Are there stats on the number of people that switched from alts to BTC? I think there are many of such people. Do you think that if there were no other carbonated drinks with sugar and caffeine in them, it would be better for Coca-Cola? I don't think so because, in my opinion, those other drinks get people used to the idea that consuming such drinks is a normal thing, and then some of them start looking for the best one in the field.
Also, a healthy competition wouldn't hurt any businessAs I said, I didn't intend this topic to turn into a debate of whether altcoins are good or bad
But personally, I think they are a good thing overall (well, at least some of them, for example, Litecoin) but then again, this is not what this topic is about. Regardless, if altcoins give more than they take from Bitcoin (ultimately, Bitcoin's value expressed in its market price), then it would mean that they add to its value (and price) as a net result. But this is exactly what is for debate here
Regarding Coca-Cola, yes, I think we can safely assume that. The inference should be straightforward. As long as people buy drinks specifically because they are carbonated and have caffeine in them, they will start drinking more Coca-Cola if there are no other such drinks around. I think this is a pretty solid assumption