Your Stackexchange.com account is not mutable; you cannot edit it. It is reflected from an account on one of the Stack Exchange community sites, like https://english.stackexchange.com/ or https://stackoverflow.com/ instead, and copied across as a central reference page.
As such, you cannot edit the 'my communities' list on Stackexchange.com either. There is no actual account to store the change in.
Sure, it is possible to add editing views to Stackexchange.com to edit the reflected info, but as Anna Lear points out, there just isn't enough call for this to justify the complexity.