Maybe you're right but this is how I read it.
Alice's writing is not strong -> Alice did not attend college.
therefore
Bob's writing is strong -> Bob did attend college.
On the other hand, what the other user deducted was:
* If you attend college -> You probably end up writing properly
* OP doesn't write properly -> He probably didn't attend college
Which is a proper logical deduction rule called modus tollens. https://en.wikipedia.org/wiki/Modus_tollens
Comfort and expertise reading, writing, and verbally communicating in English are some of the most important skills that distinguish excellent software engineers I have worked with and hired.
In many cases, those skills are even more important than technical/coding expertise--it's easier to teach and learn technicals when one's student is a fluent communicator, but a programming genius who routinely fails to explain their decisions or creations is a liability.
Somewhat ironically (or perhaps regrettably for the US education system), most of the engineers I have worked with or hired who were the most impressive written/spoken readers/communicators were people whose first language was not english, and many of the folks who struggled were native speakers/writers.
Edits: grammar, ironically.
That's not what he said. He suggested that someone who doesn't write well probably didn't attend college.