The quote there is pretty much self-explanatory, I would think, except, perhaps, that it may not necessarily be immediately clear to everyone reading it that the purpose of his use of the phrase "e duobus unus" (misprintd in the published score as "e duobus unum") was to illustrate that the work had but one dedicatee, not two - his friend the Scots poet who wrote under the name of Hugh MacDiarmid but whose real name was Christopher Murray Grieve.
His general distrust of public taste may well be enshrined in that dedication, yet accounts that I have heard and read suggest that, when the composer gave the work its world première in Glasgow, Scotland in December 1930, he succeeded in holding the audience's attention throughout and, many years later, he admitted to me that, on the four occasions when he played his music in Scotland (OC's première being the second of these), he found the audiences more engaged and sympathetic than he had expected.
Best,
Alistair