The intent for the dodge timer is that dodging for good reasons (family emergency, remembered prior engagement, trolling Lee Sin) has little to no punishment, while dodging for bad reasons (I don't like the team composition...for the third game in a row) has a substantial punishment.
Certainly, it sucks to have someone take champion select hostage. Nobody wants to play through a dumpster fire game, but Riot doesn't want people dodging for frivolous reasons, such as disliking a teammate's (legitimate) champion pick or finding trivial faults in pre-game planning. That's why the punishment exists. It is also a scaling penalty, so that people who are responsible with dodges get minimal punishment, and escalating for serial dodge offenders. Don't forget about 5 opponents who have to wait through their own queues again, and possibly 4 teammates if the dodge is for stupid reasons.