What for is to add a bad implementation of another (not strongly
required) protocol into complex browser.
Now we have a bad mailto implementation (required) and bad newsreader
implementation (not strongly required). Doubtfully some more bad
implementations are needed.
For the one hand the browsers we see now are getting to grow into
monsters. They take loads of resources (MS-Windows based for example).
IMHO, much better is to have the browser made of modules or with posibility
fork a module, mosts of them can be replaced with (or added) specialised
and more convenient to the user's choice.
D.