Why shouldn't we? A law that isn't well-defined in no law in the proper sense. Ambiguity and overbreath will just be weaponized against people and organizations the government doesn't like just like the Department of Education has done with Title VI in its crusade against a nebulously defined "anti-Semitism".
Since you bring up anti-discrimination law, I would point to the concept of “hostile work environment” as a good example. It’s fuzzy and ultimately subjective to draw the line where crude jokes become so offensive and so pervasive that they constitute harassment. But if you refused to draw any line, you’d end up with a lot of workplaces where women aren’t in practice welcome.