I see the reward but bare in mind that the reward requires 3 years of being bad AND nailing the picks. So if KP makes a superstar turn and plays you into 5-8 range, you immediately lower the odds of hitting a blue chip but even with a top 5 pick you could end up with a Darko, Thabeet or a good but not great piece like Rubio. Even if he doesn't and you hit on the next pick; you'll now need KP and other young stud to be top prospects without being good enough to beat out poorly constructed units like the Nets. On top of that, you got some teams that'll hit the trade deadline and purposely tank (like what we did), so the competition gets stiff in the race to the bottom.
Then you gotta worry about the re-ups, which can kill you if you whiff on any pick. If KP and a running mate command max money before you've loaded up the support roles or while you've got holes; you could end up with one offseason to make your big landings. I love the Blazers, but they've got A LOT of money committed already, so unless they can flip a big trade...I'm not sure that their ceiling gets much higher.
IMO, you NEED great scouts to build through the draft and they'll be successful finding you talent anywhere. I mean GS gets named a lot as a darling for building through the draft; but none of their drafted stars are top 5 picks. The Spurs are another example, they had to trade up for Kawhi and develop late picks into contributors. Or the reverse; Sacramento; they've picked no lower than 12th since 2007...Cousins and maybe WCS are what they have to show for it. Or you can look at Boston who have had over 20 picks since 2010 and yet besides Avery Bradley, their key contributors were all acquired by other means (I guess you can throw Smart in); and that's not to say they're in a bad situation...just that they've been swinging on these picks like mad and yet trades and FA has been where their core truly formed.
And none of that's to say tanking isn't a good strategy or that it can't/won't work. Just that a lot of heads act like tanking is a guarantee; but it's far from it. My theory is as simple as; a good GM will find ways to acquire talent as long as he has SOME form of flexibility. It doesn't have to be picks; it usually takes a good mix of FA's, youth pick ups and right time/right place trades...but the good ones will find a way as long as they have some room to work. Jury's out on Phil there, but I do like that he maintains flexibility; because if the Knicks hit the offseason with near max cap space, a first round pick and a growing core of good to solid pieces...a good GM will be able to build that up regardless of having the first pick or the 30th in the draft.