In "Greasy Lake," what is it about Digby and Jeff that inspires the narrator to call them bad?

In the second page of Boyle's "Greasy Lake," the narrator
provides us the following description of Digby and
Jeff:

Digby
wore a gold star in his right ear and allowed his father to pay his tuition at Cornell;
Jeff was thinking of quitting school to become a painter/musician/head-shop proprietor.
They were both expert in the social graces, quick with a sneer, able to manage a Ford
with lousy shocks over a rutted and gutted black-top road at eighty-five while rolling a
joint as compact as a Tootsie Roll Pop stick. They could lounge against a bank of
booming speakers and trade "man"s with the best of them or roll out across the dance
floor as if their joints worked on bearings. They were slick and quick and they wore
their mirror shades at breakfast and dinner, in the shower, in closets and caves. In
short, they were bad.

Most of
the descriptions here reference Digby's and Jeff's appearance
rather than their behavior. Like the narrator, Digby and Jeff are
for more interested in looking bad than really
being bad; they want to be cool.

The
first description of Digby reveals the reality of the situation. He wears the gold star
in his ear, just as a "dangerous character" might; however, Digby's father is paying his
college tuition, something to which no "dangerous character" would ever
aspire.

Like most teenagers, the narrator, Digby, and Jeff
want to be cool. Their desire to be "bad" is more of an ideal and a dream than it is a
reality. This, of course, all changes with the encounter with Bobby and the chaos that
ensues.