Pourqoi utilise t'on le subjonctif n'ya -t-il pas autres phrase simples?

Bonjour Lola,

In this case, when you want to express "(not) doing something for fear that...", I guess a simpler way to say it would be to turn your sentence differently and say "I (don't) do this because I'm scared of/that", which in French would be:
Je (ne) fais (pas) ça parce que j'ai peur de (quelque chose) / que (quelque chose ...)
I hope that's helpful!