The Bulls were in a position of power. They have a Top 20 player and were inclined to keep him through a rebuild kind of like the Pacers and PG or us and Rondo.
If I'm not selling my car, but you offer to buy it anyway, I'm going to set a high price (as most people would); as opposed to me actively selling my car, in which case, I'll set the price at market value.
I'm glad DA has been empowered (through the extension) because holding fast was the way to go. If Danny has nailed (although everyone wants to jump the gun and place ceilings on players that are young and still developing,it's stupid to make firm judgements on players that have yet to get throught their first NBA contract (see Avery Bradley's career arch)) and nails these next few drafts, he can really put this team in position for long term contender status; trading those picks for a Player could be the difference between contending for 1 year (rental bolts after year) or 15 (draft picks pan out).
A Butler acquisition (at this price) should have only been considered/negotiated if it was going to be done deal with KD. Worst case scenario (neither Olynyk, Smart, Rozier, nor Brown take a step forward this year), this trade can be revisited in a year if another star signs through FA next year.