I agree, abandon duty should have a way longer lockout, and should be progressive in punishment.
I think that half an hour is OK for the first abandonment, but the second in 24 hours should result in a one hour lockout, then a third within 48 hours from that should be a 2 hour lockout. Any time a person abandons 10 duties in a week, i think that they should have a 72 hour ban from the whole game and the forums.

This is why vote abandon was created... and vote kick.