There are some support tasks that just can't have an automatic fix. You also have to keep in mind the translation problem. The people that Microsoft hires are not native English speakers (typically) so what they said "we have a fix" is not what they mean. They probably truly do mean "I will try to fix your machine" not "we have this super duper automatic this will fix ANYTHING and we can send the hotfix to you and you can fix it yourself".
Support does remote into systems all the time. It's the most efficient way to fix things. Otherwise you'd have a lot of back and forthing and there's possibilities that you may not understand the instructions. Especially for lingering KB2919355 issues, this isn't something that one can fix WITHOUT remote access to a machine.