Eliot was fond of pronouncements, but he often changed them also. I don't know if he changed this. But it is quite possible--even a fact--that great writers can write very bad lines. Witness Eliot's own late love poems.
A major example is Hugh MacDiarmid, who simply did not edit much but published some of the most magnificent poems of the 20th Century--and some awful lines also--even some awful poems.
One of my favorite early poems is about Christmas (I won't send one of the awful ones); "The man (sic) who can write" as moving a poem of this needs no condescension for also publishing far lesser things. But he also wrote A Drunk Man Looks at the Thistle, a brilliant and important long poem--the major poem of the Scottish Renaissance.
O Jesu Parvule
His mither sings to the bairnie Christ
Wi' the tune o' Baw lu la law.
The bonnie we craturie lauchs in His crib
An' a' the starnies and he are sib
Baw, baw, my loonikie, baw, balloo.
"Fa' ower, ma hinnie, fa' owre, fa' owre,
A' body's sleepin' binna oorsels."
She's drawn Him in tae the bool o' her breast
But the byspale's nae thocht o' sleep i' the least.
Balloo, wee mannie, balloo, balloo.
Loonikie--little boy; fa' owre--fall asleep; hinny--honey; binna--except; bool--curve; byspale--child with rare or wonderful qualities, a prodigy