When a tool blurs the line between who performed the task, and you take full credit despite being assisted, that is deceitful.
Spell checking helps us all pretend we're better spellers than we are, but we've decided as a society that correct spelling is more important than proving one's knowledge of spelling.
But if you're purportedly a writer, and you're using a tool that writes for you, then I will absolutely discount your writing ability. Maybe one day we will decide that the output is more important than the connection to the person who generated it, but to me, that day has not arrived.