Footnote to Housman

To reach the top flight as a poet
you must write an unreadable work,
so obscure that your friends will forgo it
and all but the bravest will shirk.

Then the few who have read it, begrudging
the waste of exertion entailed,
will claim it's essential for judging
how far you've succeeded or failed.

From admiring their own persistence
they'll come to admiring the screed
and claim that it stands at a distance
from works that are easy to read;

while the reader who skipped it is able
to pretend he enjoyed it himself,
and leave it about on his table,
and show it with pride on his shelf.

It was Housman who worst neglected
the force of this critical rule,
with result that his faults are detected
by infants who read him at school,

while we who admire him, defenceless,
lack some pompier twaddle to quote
and can find nothing prolix or senseless
to claim as the best thing he wrote.

To learn from the fault he committed
is the first of poetical cares.
Lucid intervals may be admitted,
but be lucid the whole time who dares.

This is from Charles Johnston, Selected Poems, London, 1985. I suspect that Johnston chose the limerickacious meter to reflect his anti-pretentious meaning. I had to look up pompier, which is (appropriately enough) a pompous, and French, word for 'pompous'. I'm still not sure how to read the word 'read' in the last line of the fifth stanza: is it present tense (rhymes with 'reed') or past (rhymes with 'red')? Do infants detect Housman's poetic faults while they are reading him in school, or only later, looking back?