What makes you think his understanding (Strauss's, not Loftus's) is correct?
I don't say that Strauss's understanding is correct, but for a believer (which I think Strauss was, in some sense), it would certainly seem more plausible. The idea of an almost identical story being repeated in the same gospel (Mark 6 & 8 ) ought to give even the biblical literalists pause for thought, as also should the implied utter stupidity of the disciples. He'd chosen the buggers, after all, and they appear to be showing themselves to be the biggest blockheads imaginable, if they'd witnessed such a miracle previously, and not got the message. The metaphorical idea which Strauss thinks is being hammered home - Jesus as the Bread of Life - seems a rather more important point.
There are one or two other curious texts in the Mark account. In chapter 8, after Jesus has supposedly performed this second culinary miracle, he reprimands the Pharisees for 'asking for a sign'. What was this miracle itself if not a
sign?"[11] The Pharisees came and began to argue with him, seeking from him a sign from heaven, to test him.
[12] And he sighed deeply in his spirit, and said, "Why does this generation seek a sign? Truly, I say to you, no sign shall be given to this generation."
These words seem to indicate, as Strauss suggests, that the miracle story is a later interpolation. How that accords with the dating of the earliest manuscripts, I don't know.
The other curious matter is the concentration on certain numbers in the story, as if they had some mystical significance:
"[19] When I broke the five loaves for the five thousand, how many baskets full of broken pieces did you take up?" They said to him, "Twelve."
[20] "And the seven for the four thousand, how many baskets full of broken pieces did you take up?" And they said to him, "Seven."
[21] And he said to them, "Do you not yet understand?" "
Jeremy has already commented on Mark's fascination with the number three, in the way he groups his narrative. I get the sense that he's alluding to some ancient number code throughout, though what on earth such a code might be supposed to mean, I haven't a clue. (And it doesn't matter a hoot anyway)