The text is arguing about this expression.
Put in a more straightforward way, it basically means:

Je reconnais que je fais l’éloge d’une “littérature touchante”,
non parce que je ne saurais pas faire la différence entre la littérature
et la romance à l’eau-de-rose, mais parce que toute écriture touche,
au contraire d’un rapport, ou d’un exposé.
Par essence, écrire touche au corps.

So in this text, in some way “littérature touchante” does mean “sentimental literature”, but in some more fundamental way it does not.
My interpretation is as follows:

Some may say I am defending a “littérature touchante”,
and they are right, but not in the sense they believe.
They believe I am defending sentimental literature,
while I am saying literature
(as opposed to reports)
is always touching people in their bodies,
which is far from implying I can’t make the difference
between sentimental literature and the true literature.