When I set search-enabled="false", my input box and associated placeholder disappear. This also affects CSS that may be attached to the input box as well. My suggested fix is to move the !$select.searchEnabled logic from the ng-hide to the ng-disabled for that input box (see below):

$templateCache.put("selectize/select.tpl.html","<div class="ui-select-container selectize-control single" ng-class="{'open': $select.open}"><div class="selectize-input" ng-class="{'focus': $select.open, 'disabled': $select.disabled, 'selectize-focus' : $select.focus}" ng-click="$select.activate()"><div class="ui-select-match"><input type="text" autocomplete="off" tabindex="-1" class="ui-select-search ui-select-toggle" ng-click="$select.toggle($event)" placeholder="{{$select.placeholder}}" ng-model="$select.search" ng-hide="($select.selected && !$select.open)" ng-disabled="$select.disabled || !$select.searchEnabled" aria-label="{{ $select.baseTitle }}"><div class="ui-select-choices">");}]);