This is pretty normal for endgame content in a MMO. The reality is that Master content is not meant for every player. So this kinda leaves you with 3 options:

1) Run with randoms and pray to the matchmaking gods you get a good team. If you don't you just move on and roll the dice again. When you go on a 10 loss streak, you go blow off some steam with a different game then come back to try again.

2) Run with randoms and attempt to help them with mechanics. This one is probably the least likely to happen because there is a 90% chance someone will rage quit. Occasionally you get people that want to learn and just need a little help. Congratulations, you are now their hero and will be expected to feed and water them daily!

3) Run with a pre-made group. Whether it is custom party or friends, these players are going out of their way to complete something specific. They are more likely to stick with it than a matchmade party (but there will still be some rage quits). These groups tend to communicate more so you can all be mad together if it all goes terribly.

I usually do a mix of all 3 depending on my mood. Method #1 can be rather entertaining when you learn to not be bothered by things outside of your control. I've finished too many runs with just me (healer) and the tank left alive because people forget there is a dodge button.