Probably your English teacher would rather you were a bit more actively involved in whatever you are asked to do in class. Any way, class would be fun if more people got involved in activities. True.
In the long personal history of teaching English as a foreign language, however, I know that quiet and seemingly shy students do not necessarily hate English classes, although they find it hard to volunteer in class. At the same time, very active students may not continue to study back at home. They may not want to study, and thus they always look for some fun in class. Getting actively involved in activities is the best way to have fun. Besides, they can dominate the entire activities (not because their English is good, but other students just give in).
I kind of like a very quiet Speaking class. So long as those “quiet, shy, reserved, and introvert” students understand my instruction and make good use of it the next time they speak (into the microphone at the test center), I am content. And it does happen all the time. If there are many students who volunteer to speak in front of others, it will be fun, but I do not necessarily expect everyone in my class to have such a personality trait.
Whether a particular class is working or not, therefore, cannot be determined by the way it looks. What’s more important is whether something intellectual is taking place in a student’s system.