Of course they have.
Look at it this way: Interpreting someone's education or experience based on the way they spell can only produce flawed results in this medium.
It's a forum used by people from around the world, from many different backgrounds and languages as well as disabilities.
Using spelling as a guage means that you are assuming the following:
1) The poster is fluent in North American English.
2) The poster has received a balanced education despite their location, race, or financial disposition.
3) The poster is able to overcome any linguistic or learning disabilities.
There are smart people everywhere, it doesn't mean they're going to get the education or support they need.
I'm not attacking your opinion, just pointing out that using bad data will only generate bad results.
Look beyond the spelling at what people are saying, and the information contained within. That is the measure of their knowledge.
I can spell with the best of them, it doesn't mean my opinions on proper husbandy of Varanids is worth anything. It would look good, but I'd be full of ****