What "I need a partner" means

So today my BJJ coach was out of town teaching a seminar. During practice I was assigned teaching duties so I showed some conditioning/technical flows and some technique (more below). At the end of practice open roll started and I called for a partner. No response. There were six rounds of grappling before I left and of those I wrestled three. The folks that wrestled me are all a lot smaller than me yet we have a good technical rounds. I can count on the fingers of one hand those willing to grapple with me in a class of 30+. Back when I started and even now if someone senior to me says "I want to roll," I sprang at the opportunity, when I'm at practice I want to train as much as I can. There is no winning or losing in practice merely learning. As I get older and my schedule more full I find by making it into practice I'm just grateful and happy to be able to train. It angers me to think that people would want to take that away from me simply because they are concerned about winning or losing.

Today the flows we worked were straight arm to oma plata with your partner puling the arm out of the armlock and rolling trough on the oma plata, this was continuous for one side. We also worked on the kimura, straight, and americana arm locks from the side mount before transitioning via the knee on stomach to the other side.