From Webster:
1. The act of discriminating.
2. The ability or power to see or make fine distinctions; discernment.
3. Treatment or consideration based on class or category, such as race or gender, rather than individual merit; partiality or prejudice.
You are talking about 2. The article is talking about 3.
3. is illegal in hiring. 2. is not.
It's just that simple. 2 creates categories implicitly.
From Webster:
1. The act of discriminating.
2. The ability or power to see or make fine distinctions; discernment.
3. Treatment or consideration based on class or category, such as race or gender, rather than individual merit; partiality or prejudice.
You are talking about 2. The article is talking about 3.
3. is illegal in hiring. 2. is not.