Most famously: Why didn't the First Order just send a few Star Destroyers through hyperspace in front of the Resistance cruiser, or summon ships from one of their other fleets to intercept the cruiser from the front?
Because they were in full control and saw no need to. Why waste resources when you have to control a galaxy? Is this a serious criticism?! They were winning. With force. In fact, even Holdo shooting her ship through their command didn’t stop the decimation of the resistance. There is just one light freighter left.
Why didn't Holdo explain her evacuation plan to anyone? Why didn't she explain it to Poe when he mutinied?
Those are two questions.
The first; she did. There’s no reason to believe she didn’t. The second; do we share plans with mutineers now?!

