If you want to live in a world as black and white and clear cut as this, I don't think anything I can say will stop you.
Needless to say, it's not that simple.
Only when there is enough full-throated protest will it, maybe, slow them down or force them to reconsider.
Like I mentioned, words alone are generally not a catalyst for protest.
This is just wrong. Contests happen mostly between top 2 candidates even if there there are more in the list. I'm taking from experience of other countries in the world not usa. By that logic, of anyone who votes anything other than those 2 most popular, is like voting the whoever wins.
Even if they won't admit it to themselves.
/s
How about if they voted in a state in which every elector was already going to vote republican anyway?
Or what if they voted to protest against Harris being chosen without a primary vote, against the basic principles of democracy? (And from a party so unwilling to pay attention to the situation on the ground that it had to wait until nearly the last moment just to be able to admit that Biden wasn't going to make it.)
I can see a lot of reasons to try sending a message that way, and as far as I know Stein didn't cost democrats the vote in any state, and certainly wouldn't have cost democrats the vote nationally even if the overall popular vote mattered (which as we all know, it doesn't); your message is extremely reductive and frankly seems like a purely emotional attack. You really aren't elevating the discussion.
It sucks but in 2-party system one have only 2 choices.