My feeling is that, in any intelligent democracy, a plurality of viewpoints has to be easily accessible in whatever format people choose to access their news and current affairs - print media, online, broadcasting.
Any loss of a paper / news source that has a distinct viewpoint within this landscape - even if that viewpoint is quite a minority one - is detrimental to the whole. Amongst the broadsheets, the loss of the Independent has already left the space to the right of the Guardian vacant. If the Guardian is lost as well, then the entire sweep from centre to left is completely unrepresented in the broadsheet world. I know that it remains represented in the tabloid world, but IME people read either broadsheet or tabloid - they are not interchangeable in that sense. Those who used to read the Independent or Guardian will not switch to the tabloid of the equivalent political persuasion, they will either have to switch to a more right-wing broadsheet or rely on non-print news sources.
So while I don't necessarily agree with the Guardian's politics, I do think that the 'news and current affairs landscape', and therefore the informed nature of our democracy, would be poorer in its absence.