I dont think Read or Write at that level is what you or I thought it was. I think those columns are how many Shares the user is explicitly in the Read or Write list of.
Here is the code behind it:
foreach ($users as $user) {
$name = $user['name'];
$list = "<a href=\"$path/UserEdit?name=".urlencode($name)."\" class=\"blue-text\" title=\"$name settings\">".truncate($name,20)."</a>";
$desc = truncate($user['desc'],40);
if ($list=='root') {
$write = '-'; $read = '-';
} else {
$write = 0; $read = 0;
foreach ($shares as $share) {
if (strpos($sec[$share['name']]['writeList'],$list)!==false) $write++;
if (strpos($sec[$share['name']]['readList'],$list)!==false) $read++;
}
}
if ($user['passwd']!='yes') $list = str_replace('blue-text','orange-text',$list);
echo "<tr><td></td><td><i class='icon-user'></i>$list</td><td>$desc</td><td>$write</td><td>$read</td><td></td></tr>";
}
https://github.com/limetech/webgui/blob/master/plugins/dynamix/DashStats.page