Earlier quoted context omitted.
I don't think so. Software running on your computer has wholesale access to your filesystem. If those files are accessible only via the web (or if you bother setting up ssh + pubkey, via ssh) that significantly reduces the surface area of possible attacks. Don't hate on "not being impossible" for "being less likely."
"Less likely" applies to random events. Sabotaging or stealing code has nothing of random in it. You can claim it becomes "harder", what it does, a very small bit that doesn't warrant anything like the claims on the GP. All it changes is that the attacker will have to launch the browser or rewrite some part of it (what he can do, because the browser auto-updates with your access level), instead of simply taking the f…
Also, do keep in mind the target audience for Microsoft's enterprise products - if something lets you check off a bunch of boxes on some government or industry compliance checklist, then that thing has value to those customers, regardless of any actual security benefit.