If Robin Hoecker was intellectually honest, then she would make an effort to actually understand Ayn Rand's ideas before dismissing them as just "theory."

In her letter, Hoecker states that "Individualism works in theory, but fails when individual desires come at the expense of others." There is a very clear difference between a person who acts on his own rational judgment and a person who acts on his random, subjective "desires." It is ludicrous to just lump these two essentially different types of people into the same category and call them both "individualists." The true individualist is the person who acts on his own rational judgment. The person who acts on random whims "at the expense of others" is a parasite, not an individualist.

What Hoecker is really criticizing here is not Rand's conception of individualism, but the fallacious Nietzchean conception of individualism, which essentially advocates doing whatever you feel like doing.