Why is English spelling so ridiculous?

Spelling is one of the most difficult things to deal with when learning English. It is so problematic that native speakers often have trouble and make many mistakes. In English language schools all over the world children struggle to learn the correct way to spell. In fact, spelling competitions, called «Spelling Bees» have become very popular, particularly in the USA. They are extremely competitive, as can be seen in the 2002 documentary, Spellbound. Of course, this type of competition would be pointless in a phonetic language like Spanish. English has too many exceptions and irregularities, and may seem illogical. Why is it so complicated and nonsensical?