Yes, it's possible through an Action contribution. If you want to disable (hide) for everyone then a contribution like follows will work, otherwise if you want enabled for some use a filter to control who does/does not have access. Since you'll be overriding an existing contribution make sure to include required statements in your contribution.
<require>org.nuxeo.ecm.platform.userworkspace.actions</require>
<extension target="org.nuxeo.ecm.platform.actions.ActionService" point="actions">
<action id="SHOW_PERSONAL_WORKSPACE" enabled="false" />
:
