What motivates a guest to leave a review is fairly complicated. Think about whenever you have left a review for a product or service. It is usually related to being surprised by something being great, better than expected or awful, you are disappointed. For positive reviews, the reviewer really wants to support the business or service and sometimes that desire to support is because you LIKED the business owner. If you are a remote host it is a bit more difficult to establish rapport with guests so your being very responsive to guest communication goes a long way. Your reviews reflect you are responsive. If you look at the experience you had with the guests that did not leave reviews, is there anything that might be a common factor, for example, very little direct communication from you or to you or both?
When I read your listing description and the rules, I did not get a very warm feeling. Seemed very authoritarian and stern. Now I am sure ALL the rules are absolutely essential, but I wonder if there can be another style of communicating them. First of all, you probably have a binder of what is needed to take care of your remote cabin so spelling them out in the listing might not be needed. Suffice to say, the general rule is to follow the procedures and rules as outlined in the house binder.
Also. you have some stunning outside pictures but you should increase your indoor pictures especially to feature the bunk bed or anything else you want to highlight. Since you do not provide linens, you should be sure the pictures support that.
Good luck!