^ Yes, exactly. He actually says that there was no mention of Mecca in contemporary sources outside of Islam until the year 741.
Actually there are no mentions of Mecca inside
AND outside of Islam until year 741.
This is a pretty good video about it:
http://www.youtube.com/watch?v=ggR0Gz4JaEQI am not necessarily saying that the Muslims simply built Mecca after the fact, although that is conceivable. There may have been some sacred place known as Mecca somewhere in the desert, but noone remembered where it was so they picked any old place that had a Kaaba and made that Mecca and built a town around it. Early Muslims sources make it clear that there were many Kaabas all over Arabia.
Most likely Mecca really is where Muslims say it was. But it was probably a lot less significant than Ibn Ishaq makes it out to be, instead of a major commercial town, maybe it was just a few tents around a sacred Kaaba. That would explain why no sources mention the town prior to Islam. Ibn Ishaq simply made Mecca to be a big city because he wanted to make Muhammad seem more impressive, conquering a little village is not as impressive as conquering a big city.
The alternative is that there were many sacred sites all over Arabia and Jordan, and some of the stories from the Quran come from Jordan whilst others come from Hejaz (that would explain why there are references to the growing of olives and stuff which do not grow down in the Hejaz). We really don't have any evidence that the Quran was written by one person in one place, it could well be an amalgamation of many tales from many tribes.
I am not ruling out entirely that Mecca was exactly what the traditional Muslim account says it was, a significant and wealthy city. That is definitively possible. After all, all big things start from small beginnings. Just because there may not be any mention of Rome in the Bronze Age, that doesn't mean that the Romans made up the story of the founding of Rome in the Iron Age.
And as for the mentioning of olives and cows, well that is easy to explain away. The ancient era sources describe the region as being more fertile than they are today. There are islands in the Red Sea which are described by ancient Greeks as having forests on them, but if you look at these islands today on Google Earth, they are totally barren. Also the Arabs were traders and they traveled a lot, they would have been familiar with olives even if they did not grow in the Hejaz.