Why would they trade him?
Even with the ridiculous numbers he's putting up right now (10 points, 12 assists, 8 rebounds, 2 steals, 46% FG, 40% 3PT) his value is still low right now because:
1) He's still only 10 games returned from both an ACL injury and a broken hand
2) He's in the last year of his contract, and so any trade risks being a 1 year rental
This means Danny is likely to get offers that are far below what Rondo is worth both to him, and to Boston. If Danny is getting offers along the lines of "McLemore + 1st rounder + Filler" then I'm absolutely glad he's refusing them. Rondo is an elite player regardless of what people thing, and no GM worth anything in this league would sell short on a guy who is a 27 year old NBA champion, multi-time all star, multi-time all defensive teamer and one of the active NBA leaders in triple doubles. You don't give up guys like that for scrap.