As with anything regarding
language,
capitalization is, as
TheLady points out, a
convention.
These do change over time, but this change is slow, and we should be thankful for it--else how could we ever find anything intelligible, let alone understanding.
If we are speaking specifically of E2, there is a further consideration to my mind: our intended audience. If that is only some class of netizens, possibly in the vanguard of linguistic deconstruction in aid of a future where only our streams of consciousness are shared, that is one thing. But it is not a place I would be very happy in.
I believe there is much to be said regarding the effort required to render thought into word--even in poetry. There is nothing that is not embodied in some medium. How could we know, and understand it if it weren't? I think even prose would benefit from poetry analysis, merely a close attention to the actual object we have before us--which is all we actually have.
Language is like a river, and it does change over time; these conventions do alter. I don't think it is something we do deliberately, certainly not capriciously, but under obligation: we have a responsibility to render our wisdom in the way that best expresses it--and we often find this effort renders something we never realized we knew.
Grammatical correctness is not a burden, It is the way we show respect to those who will read our thoughts.