Speaking only for myself, I think it's because of how I would do it in Java. Without the implicit conversion to `WrappedString` which Scala offers, Java makes it necessary to take the detour through a `StringBuilder`, so a "one-liner" would not be very readable. Plus the `==` operator is strictly for referential equality in Java.
But since Scala makes it possible to neatly write it as you suggest, I will edit the article accordingly.
If you spot any instances in the OEIS where it can be rewritten as you suggest, we should probably edit accordingly.