Well it seems clear that not everyone supports Balpa recognition.
Put simply, if you support it then sign and if you don't then don't sign.
I'm not sure if everyone understands exactly what Balpa recognition would mean. I admit that I'm not entirely sure myself. My current understanding is that with Balpa recognition the Crew Council would become an elected Balpa Crew Council consisting of Jet2 pilots and that management would be legally obliged to consult with it on policy changes affecting Jet2 pilots. I don't think that if recognized all Jet2 pilots would have to become Balpa members and pay the subs.