I agree that it was a reach (I really liked PJ Hairston and felt he would be a great fit but they didn't even schedule him for a workout), but if they didn't like anyone else on the board then why not go for it. I don't think it's a fireable offense to reach for someone at #20. If this was Araujo at #8 or Jonny Flynn at #6, that's a fireable offense. Just look at who have been the 20th pick in the last 10 years:
#20 NBA Draft Picks Career Stats
YEAR TEAMPLAYER (*active)POSGPMINPPGRPGAPGPERP40R40
2013Bulls Tony Snell* SF77 16.0 4.5 1.6 .9 8.0 11.2 4.0
2012Nuggets Evan Fournier* SG/SF114 16.9 7.4 2.1 1.4 11.1 17.4 4.9
2011Rockets Donatas Motiejunas* PF/C106 14.1 5.6 3.0 .6 11.3 15.9 8.5
2010Spurs James Anderson* SG/SF195 18.5 6.4 2.4 1.3 10.7 13.8 5.3
2009Jazz Eric Maynor* PG267 14.6 4.3 1.3 2.8 10.6 11.7 3.6
2008Bobcats Alexis Ajinca* C127 11.8 4.3 3.1 .4 13.0 14.7 10.4
200776ers Jason Smith* PF/C331 16.7 6.0 3.5 .6 12.9 14.3 8.5
2006Knicks Renaldo Balkman SF/PF221 13.9 4.0 3.5 .6 14.4 11.7 10.0
2005Nuggets Julius Hodge PG/SG23 4.2 1.2 .7 .8 10.8 11.5 6.2
2004Nuggets Jameer Nelson*
Aside from Jameer Nelson, none of those guys on that list became significant contributors. Why not take a chance at #20 if these are the type of players you typically get to take at that position?