I'm quite confident that some of the security team combined with the car / transport desk are in it together with the "local cars / drivers".

Our Grab guy was shouted at when he reached the gate, made turn around and they kicked his door (I had just arrived at the lobby and saw / heard it).

We had to take the car from outside the gate and when I asked the guard what this was about (in Bahasa mind you), he sheepishly claimed that Grab is not allowed. When asked rhe transport desk they echoed it. The Bluebird we booked subsequently could come in after I had called down and informed them.

As you said, no management oversight to note. Never meet anyone higher than an assistant manager during a 4 night stay. Decent on points, but a no go for those cash rates they dream up most of the time. Way better options around for that kind of money.