Surely it depends on each individual case. For me, it saves me time if my clients can have access to certain aspects of their WP Dashboard, so that they can add pages, posts, etc. Also, if they're adding pages and posts, they'll want to be able to add these new pages to their navigation menus, etc.
Thankfully, there does actually exist a plugin that lets you choose what areas of the WP Dashboard you want your Editors to see. It also allows you to completely brand the Dashboard for a more professional look and feel.
The plugin is called White Label CMS and is available here - http://wordpress.org/extend/plugins/white-label-cms/
I hasten to add, that I am in no way affiliated with the author(s) of this plugin and I am not getting any commissions or royalties for recommending it. I have merely recommended it because I use it and find it very useful.