To be clear, I don't do self-upvoting.
Now, that being said, I don't deem it's wrong to upvote yourself. It's freedom of choice. Our voice. Every user's choosing. Now, is it driven by greed? I can't answer them.
But, as you present the example of Pepsico, sure, if they packed with One Million dollar, single upvote would produce enough rewards for them. Good for them I surmise. And, I think, that's the motivation behind the action. After all, you have to understand the factor of "money."
Now, having said that, I kinda, prefer not voting of our comments. On a post/article, I guess, okay (fair to me). But, when you comment on someone's post, you appreciate the work of someone (if not criticize). The content of the post. Not the intent of making rewards out of it. I would say, it's not a good curation. It's an intention-driven attitude- And, that's just me.
For instance, in this very article, I can comment,
|This is an interesting article
And upvote my comment. Who cares. I will get my share and done with it.
You see the point. Here my intention would be to get rewards. I don't add any value to your writing. Your post. Your content. Your thought.
And, this to me is not a healthy sign for the community to grow.
But, as I said, it's one's will and freedom. You and I can't stop it. Of course, none of us is trying. It can be the guide. If we have to stop it, we have to make the changes to the code and have it enforced for all.
If not, it's okay to have this option. It's ultimate users call.
Lastly, I do want to mention; it's a different type of article. Often user asks, including me. You just pen them down. Good thought. @intelliguy