I counter this logic with...
Winnipeg, Florida, Columbus, Ottawa are not in the same catagory as the Leafs as the Leafs will be able to spend to the cap when needed and will be able to retain their blue chip prospects.
Dallas, Buffalo have not tanked and drafted blue chip prospects. Only recently has Buffalo finished really low and it's too early to tell where they will be.
Edmonton is the classic case of a tank gone wrong.
I would say look at teams like Pitts (crosby, malkin), Chicago (toews, kane, keith), LA (doughty, koptiar), Van (Sedins) who were able to draft blue chip prospects and build around them.
There are no guarantees either way but which method of development has a better chance of building a consistant stanley cup competitor?