It is not a feature, but you can disable it by doing the following:
Open (in FTP) /osticket/include/client/tickets.inc.php
There, change the following: (Line 79-83)
<td nowrap >
<a href="view.php?status=open"><img src="images/view_open_btn.gif" alt="View Open" border=0></a>
<a href="view.php?status=closed"><img src="images/view_closed_btn.gif" alt="View Closed" border=0></a>
<a href=""><img src="images/refresh_btn.gif" alt="Refresh" border=0></a>
</td>
<td nowrap >
<a href="view.php?status=open"><img src="images/view_open_btn.gif" alt="View Open" border=0></a>
<a href=""><img src="images/refresh_btn.gif" alt="Refresh" border=0></a>
</td>
And then in osticket/include/tickets.php
Change this: (line 263)
$nav->addSubMenu(array('desc'=>'Closed Tickets','title'=>'Closed Tickets', 'href'=>'tickets.php?status=closed', 'iconclass'=>'closedTickets'));
to this:
if(!$thisuser->canManageTickets()) {
$nav->addSubMenu(array('desc'=>'Closed Tickets','title'=>'Closed Tickets', 'href'=>'tickets.php?status=closed', 'iconclass'=>'closedTickets'));
}
(Hasn't been tested yet, try it out please )