Academic papers put a new perspective, a new voice into the world. If they are not read, than they are not heard. All the work and research that goes into the academic paper is not put to use in the world. The writer of the academic paper might receive their accreditation but that is not what the academic system should support if their voice is suppressed.
The purpose of this is not for everyone in the world to read it. Honestly most people are not going to understand what is being said in the article and the writer knows that which is why they write to a specific audience, which are usually authorities in the field who have an interest in things like this.
If I were to write an academic paper, and nobody was to to read it, I would still gain some knowledge from writing the paper. Academic papers require students to do research. By organizing this research and putting it into a paper, the students are enriching their education. So what if only the teacher reads it?
Terrible newspapers in the UK such as The Sun get very high reader numbers, doesn't make them worthwhile or useful. Lots of academic papers get low amounts of readers but thats because of who they are targeted at and their topics. What if only 10 people read an academic paper but all found it incredibly useful and took it away and went on to do brilliant things with the knowledge gained from the academic paper. The fact few people read them is irrelevant, how useful they are to the readers is what matters.
No, it is not a waste to write academic papers if very few people actually read half of them. Yes, they are a snore to read in their entirety, but a lot of academic papers have crucial information, innovative ideas and critical thought that could very well be the foundation for a new invention, medicine or movement.