What? Where have you been that you have this kind of opinion? It’s basically the same as reddit: You do have your bubbles, you do have open minded communities, you also have closed minded communities. Your experience is therefore dependend on where you go.
For example: Joining a vegan server to say “meat is great” will lead to a shitshow. But that’s not supprising and it’s not because Lemmy per se harbors militant people.
This should be a legit tactic. I’m selling these tubes next year to my neighbors to see how well the product is received