Sqad...I can say with complete certainty that if you asked me to join you in an armed robbery, I would turn you down, and then report to the Police at the first opportunity. That I think would take the b*lls, not coming on the robbery. Of course, most criminals don't do that but I have no criminal tendencies whatsoever, so perhaps I am behave differently.
Biggs was a career criminal, not some cheeky-chappie, who was quite a good sort really, kissed babies, was good to his old Mum, etc but made one mistake and that was getting caught.
As regards people who "admire" the planning around a crime but despise the crime itself, I look forward to plenty of similar comments when Ian Brady dies. After all, it must have taken considerable "project management" to plan their crimes.