We keep MultiMC open source because we think it's important to be able to see the source code for a project like this, and we do so using the Apache license.
Part of the reason for using the Apache license is we don't want people using the "MultiMC" name when redistributing the project. This means people must take the time to go through the source code and remove all references to "MultiMC", including but not limited to the project icon and the title of windows, (no *MultiMC-fork* in the title).
The Apache license covers reasonable use for the name - a mention of the project's origins in the About dialog and the license is acceptable. However, it should be abundantly clear that the project is a fork without implying that you have our blessing.