Completely removing the User Profile Service Application will prevent you from taking other benefits of the Service.

If you do not want the My Site option to be given to users, you will have to go into Central Administration > Application Management > Manage service applications > User profile service application > Manage User Permissions (ribbon) and set appropriate permissions.

refer: http://howtosharepoint.blogspot.com/2010/11/hide-disable-my-site-my-profile-and.html