Despite openly naming themselves as “dissidents” and pretending to be “scientists”, the main issue with Arek’Jaalan was that they were outright thieves (they did hijack a whole freighter) and traitors (they ran and operated from Minmatar Republic, which is in a state of war with Caldari State).
There is no greater crime and disgrace to any human being than a treason.
Those who supported that criminal group in the past or still dare to support them are outright amoral and repugnant.