If the Qur'an is so good why is it written so it is so easily misunderstood?

The Qur'an was revealed and written in the 7th century giving people guidance. The target audience were bedouins who had the Arabic language of the time. A 7th century Arab had no problem understanding it.

But the language evolved over 1,000 years, the Arab world grew and there was a massive influx of non-Arabic speakers to the community.

To understand the Qur'an one has to look deeper to understand what it meant to the 7th century audience of which it was part of a long discourse. The historic context is not included because it was known to everybody at the time.

However, this form of interpretation is complicated and hard to understand for many. That's why some tend to interpret it literally (as in any other religion). No book can be taken literally and remain valid.

Take a look, for example, at William Shakespeare. His work is less than 500 years old, but without knowing the English of the 16th and 17th centuries and without knowing the historic context of his time one vcannot understand Shakespeare. The same applies to the bible.

That's why it is pointless for anyone who doesn't have knowledge of the time and the historic context to try to read the text and make a lot of sense from it. They will inevitably make up their own interpretation and it will be far removed from the Islam of the Prophet.