Because once the White Sox added him to their 40 man roster when they called him up in August 2010, he was never sent to the minors again. He never burned even one option year (technically, he has 3 remaining).
Any time spent in the minors before you are added to the 40 man are not option years. Any years you spend in the minors after you are added do.
There is another provision though, once you have 5 years in the big leagues, you can’t be sent down without your permission. So while Sale has 3 options remaining, they are meaningless. Ditto a guy like Bogaerts.