SAN DIEGO — A plan to temporarily place an observation wheel in Balboa Park has been abandoned by proponents who are pointing to city bureaucracy and a vocal opposition group as insurmountable roadblocks. “Regretfully, four months into this journey and after many hours dedicated to community outreach and responding to the city’s endless list of project action items, we’ve decided to walk away from the Balboa Park Star,” proponents said in a statement. The brainchild of David Cohn of the Cohn Restaurant Group, the so-called Balboa Park Star was intended as a pandemic-friendly activity that could promote more foot traffic in the park at a time when many of its other attractions — museums and restaurants — have limited or ceased their operations because of state and county regulations.