We were in Morocco a few years ago but as it was part of a cruise and only a 24 hour trip we didn't need any cash.
As you say, you take cash, Sterling or Euros, and they will exchange them at a few places.
Because it's a closed currency, you can't buy dirhams in the UK or any other country outside Morocco. Most travellers take pounds sterling and exchange them in Morocco. You can also withdraw dirhams from an ATM, either with your own bank card or a Travelex Money Card.
You being negative about something made up or that at the very least have no knowledge of, is not the same as someone being negative about his on field performances that are there for all to see.
Tried to be clever. Failed miserably.
We’ll leave it at that.