To be fair, about:memory is designed to be used primarily by Firefox developers. Some web developers will be able to use it effectively, but it is quite intimidating.
Happily, memory profiling tools designed for use by web devs are being actively worked on.
To be honest, it is impressive the kind of detail about:memory manages to provide. But yes, it can be fairly intimidating. That is the problem I tried to address when I tried building a D3 backed front-end over it[1].
Happily, memory profiling tools designed for use by web devs are being actively worked on.