Is there in Mark an INTERESTED focus on the humanity of Jesus?

[Giuseppe]

I am undecided if this book is worthy of its price or not.

While I admire sincerely the enthusiasm of scholars who emphasize the paulinism in Mark, I am frankly perplexed when I read in particular:

the “cross of Jesus is essentially directed against all religious illusion and brings man to recognise his own humanity” (43).

(my bold)

Marcion wouldn't have found a more fiery adversary.

[Kunigunde Kreuzerin]

... I am frankly perplexed when I read in particular:

the “cross of Jesus is essentially directed against all religious illusion and brings man to recognise his own humanity” (43).

(my bold)

It seems to me that Diaz and you have two different aspects in mind. Diaz's brief quote seems to be about Mark's issue of man's place in the world and in relation to God, while you are rather discussing the Marcionite question of Jesus' divine or human nature.

[Giuseppe]

I interpret Diaz's quote as saying:

“the cross of Jesus is essentially directed against all religious illusion [against docetism?]

and brings man to recognise his [of Jesus?] own humanity”

You say that "his own" refers to "man", not to Jesus.

Even if your reading is correct, it remains however the strange focus by Mark on the cross "directed against all religious illusion": an implicit polemic against docetists, according to which the humanity of Jesus was only an illusion, his revelation being the only thing worthy of value?

This would have implications on the Messianic Secret: you don't hide something (=the divine nature of Jesus) unless that "something" is emphasized by rival sectarians as being in antithesis against all your previous belief.