You can have a pretty good Java web server going in about 200 lines of code.
No, you can't.
Your "simple HTTP server" proposal is roughly on a par with suggesting that a web developer should design his own security protocols. The idea is simple enough, but there is a lot of subtlety involved in covering all the edges cases properly, and a lot of very smart people have spent a lot of time building, testing and maintaining good tools for these jobs. Why would you reinvent the wheel, with a flat edge across part of it, a single spoke connecting to the axel, and in only one size that won't be the one that fits under the arch next week anyway?
No, you can't.
Your "simple HTTP server" proposal is roughly on a par with suggesting that a web developer should design his own security protocols. The idea is simple enough, but there is a lot of subtlety involved in covering all the edges cases properly, and a lot of very smart people have spent a lot of time building, testing and maintaining good tools for these jobs. Why would you reinvent the wheel, with a flat edge across part of it, a single spoke connecting to the axel, and in only one size that won't be the one that fits under the arch next week anyway?