Both as a former team-sport athlete and as a sports fan, I find it shocking that they are giving up the opportunity to improve their skills by playing a tougher team. The truth is, they've lost all their games this season, so I can see how they might feel demoralized.
But unless they want to give up and shut down their team, they are going to keep playing and they are going to keep losing. At least sometimes, because that's how it is for most of us!
When I first started out as a speaker, my audience was teenagers. And I was terrified. I was intimidated. I couldn't imagine making any kind of an impact, or even connecting with them at all. I don't even remember my first experience talking to a classroom full of teenagers; I must have blocked it out.
However, I kept going. (Well, I had to. It was my job.) I kept showing up. I kept tweaking my presentation to make it better. I learned from these high school students how to meet them where they were, how to engage them, how to understand their needs as an audience. I did it for six years. And in the interest of not repeating myself too much, I will direct you to the post I wrote about why you need real world experience, and what I learned from it.
Don't avoid the difficult audiences because you're afraid. Don't shy away from trying something new and hard because you fear embarrassment. If everything you do is easy, you will never grow as a speaker.
We all fail from time to time, but failure is nothing more than a learning experience. Keep learning, keep trying, keep fighting. You will succeed.