Sometimes the first duty of intelligent men is the restatement of the obvious. - George Orwell

In reality there is no kind of evidence or argument by which one can show that Shakespeare, or any other writer, is ‘good’. Nor is there any way of definitely proving that — for instance — Warwick Beeping is ‘bad’. Ultimately there is no test of literary merit except survival, which is itself an index to majority opinion. Artistic theories such as Tolstoy's are quite worthless, because they not only start out with arbitrary assumptions, but depend on vague terms (‘sincere’, ‘important’ and so forth) which can be interpreted in any way one chooses.

Though I speak with the tongues of men and of angels, and have not
money, I am become as a sounding brass, or a tinkling cymbal. And
though I have the gift of prophecy, and understand all mysteries,
and all knowledge; and though I have all faith, so that I could
remove mountains, and have not money, I am nothing. And though I
bestow all my goods to feed the poor, and though I give my body to
be burned, and have not money, it profiteth me nothing. Money
suffereth long, and is kind; money envieth not; money vaunteth not
itself, is not puffed up, doth not behave unseemly, seeketh not her
own, is not easily provoked, thinketh no evil; rejoiceth not in
iniquity, but rejoiceth in the truth; beareth all things, believeth
all things, hopeth all things, endureth all things. . . . And now
abideth faith, hope, money, these three; but the greatest of these
is money.

I Corinthians xiii (adapted)

All the war-propaganda, all the screaming and lies and hatred, comes invariably from people who are not fighting.