What Brad Stevens has done is a good thing without a doubt. The whole idea of chasing picks to get that "franchise" guy, lose games and lose your supporter base to too much of a high risk.
If the celtics tanked this year, they probably would have been the 5th best at it (Philly, Minnesotta, New York and Lakers would of sucked more). In the last 10 years, of the top 5 picks in the draft, ZERO have won a championship. You have to go back to 2003 when LeBron, Bosh and Wade were drafted to get a top 5 guy to win it all. Sure in that time teams have got Kevin Durant, Blake Griffin, Anthony Davis, etc but teams have also taken Hakim Thabeet (#2), Anthony Bennett (#1), Greg Oden (#1) Alex Len (#5), Thomas Robinson (#5), Adam Morrison (#3), etc. So getting a top 5 or 6 pick doesn't guarantee success.
In the last 10 years of the draft championship contributors such as Kawhi Leonard (#15), Rajon Rondo (#21), Danny Green (#45), Tiago Splitter (#28) have helped their team considerably more. Then you can get diamonds in the rough like Rudy Gobert (#27), Greek Freak (#15), Jimmy Butler (#30), Chandler Parsons (#38), Marc Gasol (#48), Jeff Teague (#19), DeAndre Jordan (#35), Serge Ibaka (#24), Nicholas Batum (#25) and a lot more that I can't be bothered typing.
Seeing as getting a top pick doesn't matter, wouldn't it matter more if a team could attract top free agents this summer. If you are LaMarcus Alridge would you rather play for a team like Philly who aim to lose or for a coach like Stevens who can win with average players. I think having a coach who can win becomes a main draw card for Free agents, plus being in the east which is easy, plus the celtics being a historic franchise. Kevin Love will probably look at them, probably Greg Monroe, Goran Dragic, etc.
Additionally, the crazy thing about Boston is that Gerald Wallace is the highest paid player. If Danny Ainge can work wonders this summer it would be to trade Wallace's ($10m) next year (or amnesty it), trade Brandon Bass's $6m and to dump those contracts he may have to give up some pieces but then I hope he goes really hard after LaMarcus Alridge, DeAndre Jordan and a wing say Danny Green.
A team that looks like this under Brad Stevens would be so much better than having pick 5 in this draft which may be Kristas Porzingas or Justice Winslow.
G - Marcus Smart / Thomas / Pressey
G - Danny Green / Bradley / Young
F - Evan Turner / Crowder / Datome
F - LaMarcus Alridge / Sullinger / Jeberko
C - DeAndre Jordan / Zeller / draft pick
Dump or trade out Wallace, Bass, Olynck, one of your first round picks this year (maybe keep the Clippers pick that they have).
That team in the East with Stevens would contend for a championship. To me it looks like a better defensive team than the Atlanta Hawks. The only other thing you may do it try and get a defensive SF instead of Datome who can guard LeBron.