First, if John doesn't hate computers very much, but he doesn't like history as much, and he has a good understanding of science, computers are actually a good choice. Many people learn it and find that they really like it. Computers have a bright future. If you are engaged in computer employment in the future and earn a good income, you can buy more history books. Personally, I think history is not like mathematics. It is difficult to teach yourself without a teacher. Of course, this does not mean that history teachers are useless. Of course, a good teacher will give you a lot of knowledge that books can't learn. It's just that if history is just for fun, it's ok to read history books. Sometimes what you like now will be boring if you learn more.

Second, if John himself doesn't like computers or has a poor foundation in science, he can choose history. Interest can often make him go further. Of course, choosing history may mean that it is more difficult to get a job, but if you really study it, it will be great to become a top scholar.

The above premise is that the computer major you mentioned has a good future. In fact, at present, too much computer science may not have a good future.