people who only know Che from the t-shirts obviously
the Che t-shirts make him look like a badass revolutionary freedom fighter

There's also people who know the full rundown on Guevara and other such "heroes", like Mao and Stalin, and still genuinely think of them as heroic and/or someone they should follow their footsteps.

I feel like certain ideologies enable people who would just want to "embrace being an evil chaotic dick waffle", a rebel WITH a cause, or better yet, a convenient excuse.