Writing and editing are related, but different skillsets. FASA used to have a staff editor who did *no* writing, but she had teh Red Pen of Doom and would reach in there to make corrections.
For the record, as bad as you might feel about writing errors in books, the people whose names are attached to said errors *really* get belly-twisted over it. We catch as many as possible, but every now and then something will slip through (Especially for word mistakes, like peak instead of peek, or throw instead of through, since spellcheckers pass those by and looking over your own work, your brain will trick you.)
There are some changes coming down from above to try and fix this. Personally, I'd love to get Jennifer back on staff again, but I don't know anything about Catalyst's finances in terms of feasability on the issue.
But, the problems have been noted and ways to correct it are being attempted, but we're not where we need to be yet. Hopefully soon.
(For the record, when we finally get abook out that's mistake-free, I will probably ask for everyone to give me a cookie at GenCon. Just 'cause.)