Why is using the rails default_scope often recommend against?

Question

Everywhere on the internet people mention that using the rails default_scope is a bad idea, and the top hits for default_scope on stackoverflow are

Answer 1

For me is not a bad idea but must be used with caution!. There is a case where I always wanted to hide certain records when a field is set.

1. Preferably the default_scope must match with the DB default value (e.g: { where(hidden_id: nil) })
2. When you are totally sure you want to show those records, there is always the unscoped method that will avoid your default_scope

So it will depend and the real needs.