Why do academic papers have so little personality?

They are supposed to have little "personality" because they are about the topic, not author.

A proper academic report or a text-book, especially on a technical subject, intended for a serious publication should be interesting to its intended readers, but still passive. The observations, ideas, tests and conclusions are what matter, not the author's personality, no matter how passionate.

A very occasional personal phrase like "We found that..." is permissible, as shorter and smoother than "It was found that...", but the general tone is normally impersonal.

You might make and publish a significant extension to your area of knowledge, but most of your readers won't know you as a person. They will respect your work, and you, but otherwise you and most of them are strangers to each other.

If you are writing or speaking for the general public, you may have to pitch the level for an audience who is intelligent but won't necessarily have your deep background knowledge of the subject. Also you want your audience to share your enthusiasm, even be inspired, so then a less formal approach would be appropriate.

If you are lecturing to a specialist audience I think you would still deliver it in a more personal style, though at their level of prior knowledge. You are a person standing in front of other people, talking to them, not an android!

A book or paper about linear algebra is a book or paper about linear algebra. It's not about whether the author is married or not, or whether his wife cheats on him or has big boobs. Almost anyone who is interested in the subject of linear algebra couldn't care less.
Actually we even tend to use the author's name instead of the book's name, so we say, for example, "the Ashcroft-Mermin" when we refer to those authors' solid-state physics book. There's a ton of solid state physics books, but there is only one Ashcroft-Mermin. Do you have the Ashcroft-Mermin?– Yes, over there, it's on the left shelf.

It's the type of writing, like people just want the facts, like technical writing is the same

Academic papers are supposed to be mainly research, reason, logic, detachment and clinical views.

Objectivity is essential to academic study. You can write on topics that you are passionate about, but you must take a step back and separate your opinion from dispassionate analysis. Studying at a higher level requires you to deal with many different points of view and draw conclusions from your analysis of the material. Doesn't necessarily follow that your writing will be dry and boring.

What are you studying? If you want verve and style, then you need to do literature. Nothing is lifeless if you have something amazing to say. But then, academia is a dead place when it comes to creativity. There are research papers written by PhDs that no other PhDs even care to read.

I still had my unique writing style when writing academically. In my case clarity was what made my writing ... apparently quite noticeable. I think because everything needs to be factual and justifiable scientifically, they're written without emotion.

personaiout is not FOR academic reaserch. it is to put ones work where others in the field can see it
it is not about YOU or personality
it IS about your work
and the sytem of peer reveiewd academic papers, is not a place to socialize
you can most often find the authors and hey write to them if personality is what you want

My friend included metaphorically significant tips and recipes for cooking his favorites inside his math thesis and he got his PhD.
His was one of about five of those papers I actually read, because it wasn't so dry and boring.

"Boring Method." Godd/great writers can transcend. I dropped Political Science as a sophomore due to horribly boring writers.

Change ur perspective about the topic or talk to ur professor

Perhaps academia is not for you.