Blu-ray's DRM Pixie Dust Defeated

Why do people persist in believing that DRM can ever be effective for long?

A small group of dedicated researchers over on the Doom9 forum have successfully defeated BD+, the Blu-ray copy-protection system. This was the copy-protection mechanism that Richard Doherty, a media analyst with Envisioneering Group, claimed wouldn’t likely be broken for 10 years.

Not that any cares about Blu-ray, of course.