Faucet bots are not really fair to others but that is not the main reason why you shouldn't use it. The main reason is the simple fact that you will be banned. And if you are using the account for anything else, all of it will be gone when you get banned and that is not something you would want. Sure, it is unfair to others but people who use faucet bots do not care about fair or no fair, they only consider themselves and you can't convince them by saying they should do the right thing, they already knew the right thing and ignored it to begin with.
But what can change their mind is the simple fact that they would be banned, everything they have will be confiscated and not given back. After that they come here and cry about their account being blocked, but that is what you get when you use that kind of bot.
Sorry if I was rude, but I still couldn't figure out what the hell you're trying to explain here

What the hell is fair and unfair here

We are talking about using bots to get free bitcoins. It's free bitcoin for everyone, why is it unfair? Just avoid the abuse, it is okay. One person develops the bot to replace him, and one can't develop the bot, and then the person who can't develop the bot says it's unfair?