No…'fraid not. They’ve been this way for many years. They are probably content that way, and if you try to make them do a 180, you may end up causing a lot of tension and bad feelings.
You say you have respect for your inlaws which is good…so respect their way of life. You can inject some fun into the lives of your husband and his family which I’m sure will be refreshing for them. But don’t try to change them. Like others have said, it’s about compromise. Invite them over for fun events/outings and OCCASIONALLY, insist (in a loving and respectful way) when they are reluctant to join in. And other times, understand when “no means no” and be gracious about their refusal while still leaving the door open for fun on another day. Hopefully, they will be just as respectful as you, and try to compromise on their quiet lifestyle as well.