Hmm... In the case of iptables I think you're right that _name_ would do, but if anything, this is a less typical case. I would say the most common use case would be the sending of multiple emails. On both iptables and sendmail, generally the _name_ tag is being used to represent the jail name.
Also, when querying with fail2ban-client to get a list of actions, I think the action being named with the "bandaction" (e.g. iptables-tcp and iptables-udp) is clearer.