Let's review the Leafs first picks for the last 20 years..
2010 - Brad Ross
2009 - Nazem Kadri
2008 - Luke Schenn
2007 - Dale Mitchell
2006 - Jiri Tlusty
2005 - Tukka Rask (as a side note, Phil Oreskovic was picked next by the Leafs...)
2004 - Justin Pogge
2003 - John Doherty
2002 - Alexander Steen
2001 - Carlo Coliacovo
2000 - Brad Boyes
1999 - Luca Cereda
1998 - Nik Antropov
1997 - Jeff Farkas
1996 - Marek Pozmyk
1995 - Jeff Ware (couldn't wait to throw that one out there..)
1994 - Eric Fichaud
1993 - Kenny Jonsson
1992 - Brandon Convery
1991 - Yanic Perreault
1990 - Drake Berehowsky
Looking back at it, a few of the players they drafted after 1998, when Pat Quinn started and things turned around a bit, actually turned into fair NHL'ers. Problem is, not many of them turned into much more than bottom-half NHL players. Before 1998..ouch..pure luck they got anyone at all.
So not the best scouting..not the best development..not the best trading record... I don't think the scouting was terrible..but they've had poor draft positions after trading away first rounders and they just didn't either pick or develop what picks they had all that well.