Why is spelling so important?

There's an alternative system of spelling and teaching reading called the ITA method which was introduced in the 60s to 70s but was abandonned because of the difficulty of transferring to the orthodox system.
"The I.T.A. remains of interest in discussions about possible reforms of English spelling."
from wiki.
jangran good quote!

We’re too accepting of poor spelling, punctuation and general use of English these days. The problem as I see it is that young people don’t seem to want to read anymore. Reading develops good spelling and punctuation. I would be severely dismayed if we lived in a society where the only people who could spell, and use English properly were people who had learned it as a second language.

I’m an absolute bookworm and value correct spelling, but my daughter is dyslexic and I have a great sympathy for that condition. It is no use suggesting that people should read more if they have no desire to read. Thank God my daughter has lots of enviable practical/socialising qualities which more than make up for that deficiency. and thank God we are all different and contribute in varying ways to the tapestry of life.
Many famous authors were bad spellers.
I have dyscalculia and maths at school were an absolute nightmare. I still get hot and bothered by money matters, love the euro and cannot haggle in a place like Turkey with all those noughts (stops me buying things?) but there seems to be no stigma over numbers. I wonder why this is?

I usually spell well and look up anything I don't know. What I don't understand is why people do not use spell check on their computer, pads or phone as they autocorrect. DH sister is the worst for this and sometimes things do not make sense. They exchange emails every day and it drives him mad!