I have gotten to the portal first on multiple runs and noticed that the other players markers are not moving. When this happens I will go and see what has happened as they may of hit a trap etc. It is common sense not to stay at the portal waiting and don't feel he had to say something. Also the OP said this is happening to him on a regular basis which makes me think it is more his problem than the other party members.

I am also going on that me and the other 3 members regularly split up on floors 1-30, but it also depends on the party set up sometimes it isn't possible on floor 21-30. I have never experienced the problem the OP is having and I am working on my 4th weapon. Only time I have seen kick coming in was on floor 41-50 but then when I explained they can force DC instead of abandoning/requesting kick before boss they stuck around and killed the boss instead.