The academic study of government is extremely important. Back when I was in high school, I really disliked the government courses we were forced to take, however they are an important beginning to what can actually be a very interesting education.
As an economics major, I have really been able to see the importance of the government, the decisions they make, what they represent, how they operate, and how they are viewed. Whether it be criticizing a government for not taking enough action, or intervening too much when they should stay out of the issue, people always have and will continue to debate the purpose of each government.
However, what can be noticed around the world, is that successful and largely developed countries, always have an established government institution. On the other side, poor and developing countries that are unable to escape poverty, or see constant corruption, may not have the proper institutions set up. Yes the government is far from perfect, but understanding their importance in the world can not be understated.
In high school, much of the academic subject that is government, focuses a great deal on the judiciary/legislative/executive side of things. It looks at more domestic issues and how it affects the people of that country. However, where high school education fails to elaborate with the academic subject of government, is the importance it has to the world, justice, business, economies, education, science, and almost everything else. The government plays a role in almost everything in life. Who do you think funds that high school education you're getting at a public school? The government. Who has helped fund for scientific research in the cure for various diseases? The government. Who do you think pays the firefighters who just rescued people from a burning building? The government.
I know a high school course in government may not be the most engaging class you take. However, the importance of understanding the government and its processes at a young age has its benefits. It's not until you either take more advanced classes, or read the news to really understand the importance behind it all. That's not your fault though. It's just a problem with the class being offered.
There are many reasons why the study of government (also known as political science) is an academic field of study.
First, you can look at the importance of the field. In most countries, governments have a great deal to do with the welfare of the country. Therefore, the study of how government works is of great importance. It is important to understand, for example, how various kinds of government actions impact their societies.
Second, you can look at how complicated the topic is. It is very difficult methodologically speaking to study government. One must figure out how to isolate the variables one wants to study. For example, if you want to understand the impact of various voting systems (like England's first past the post system vs. Australia's alternative voting system) you have to be able to determine which of the differences in the two countries' systems are due to voting systems and which are due to other factors.
So, political science is both important and complicated. For these reasons, it is an academic field of study.
Because it is complicated and requires lots of study. It's also a very important field to study. Government is an important field since all countries and society relies on it.