Web assembly is about liberating the browsers from a particular development paradigm. Developers are people. We come from different cultural and philosophical background. We also have so much in common. The very crux of the advancement of any technological field is the liberty to be able to innovate and devise new ways of doing things that breaks long held mainstream views and practices.
Having a standard or some kind of constraints is important. The question is what level of constraints should we impose on people so that it doesn't hinder innovation and growth. Too much constraints will force people to come out with complex schemes to get around it. Case in point: today we have multitudes of frameworks which seems to be based on the underlying premise of to allow users to do things that the standard makes it hard to accomplish. Of course opening up the browsers for other languages will not stop the proliferation of new frameworks and libraries but these frameworks and tools will be developed for the right reasons. There should be 99 reasons to develop a framework but circumventing the standard should not be one.
I'm a proponent of WebAssembly because it is a convergence point that allow people to to innovate, work and manifest their ideas in ways that suit them best yet still allow them to produce something that's inter operable everywhere.