@Levente6 Star ratings are very subjective. It's rather egotistical to insist that every guest consider9 your place to deserve a 5* rating just because you think it does.
That said, you may indeed have a place that always deserves 5*s and obviously the majority of your past guests have agreed, which you should be thankful for.
I can understand your irritation if you are pretty sure this was an intentional act by the competition to harm your business. But it seems to me that if that was the intent, the star rating would have been much lower than 4*s.
This isn't some huge deal exclusive to you- tons of hosts get low star ratings they don't deserve. It's too bad, but not something to dwell on.