System Field: Issue Type - only icon is displayed in issue navigator

(a) When viewing the results of a filter on a portal page via 2-dim. filter statistics, for the system field 'Issue Type'
not only the ICON is visible, but the NAME of the issue type is available, too.

(b) When viewing the results of a filter in the issue navigator, information on the system field 'Issue Type' is ONLY available as ICON.

As we use approximately 20 different sub-task types, there's no use in having a different icon for each sub-task type.
So they all have the same icon. JIRA-behaviour (b) makes it impossible to distinguish - at a glance - between different
sub-task in a list in the issue navigator. See attachment.

Can this be changed at all? If yes, how?