An IOCCC Judge here. Sure, a variety of things! A competition can take about 4 full weekends of time ~128hrs total (Fri:6+Sat:16+Sun:10 x 4) to set up, judge and release the results. Getting 3 independent and very busy people coordinated with work, travel and major life events going on can get quite difficult. Recently we've opted to not start a competition if we do not pre-schedule the weekends for completing it! The result is that 2016 and 2017 could not happen.