Beltran flew with the Giants to the all star game. I suppose they didn't like what they saw, therefore he won't be going there.
That, or the Giants don't want to pay what the Mets are asking.
Personally, I think the Giants should try to get Reyes as he addresses a much more glaring weakness in the Giants' roster, but the Mets will want even more for him. I don't think Brian Sabean will be willing to give up a Jonathan Sanchez, Brandon Belt or Zack Wheeler for a rental.
And anyway, the Giants did trade for Jeff Keppinger yesterday, which should be a sufficient reinforcement for their infield. Hope the old "great pitching and just enough offense" strategy works as well as it did last season...