In early elementary school, the 220 sight words will get you a long way. In high school and college, they might not be enough and if a person does not have basic phonic decoding skills, they could well have problems.
I would not want my children taught only or even primarily a sight-based reading system. I want my children to learn the phonetic mechanics of reading, even if it's complicated and at times confusing. I'd be five kinds of pissed if this area of their education was neglected.
This study was done in 2001 with only 86 students. Have there been broader studies or long-term follow up? I would hope that such would be the case before 90% of students' educations were tinkered with for the benefit children who could simply have their own reading group.
My sons are autistic and sometimes they need some special accommodations, but I can't imagine expecting the rest of the student body to have to take time out of their day to do social stories and talk about 'expected' behaviors, etc.
Those kids know that "My head is a pig!" is not an appropriate salutation. My son, OTOH, needed a little help figuring that out. I wouldn't want him taken out of advanced math because a couple of the kids in his class were struggling with math, so it's only fair.