There's truth to that, for sure; but building teams and coaching them to Championships are two different things. Scooter had the team in 1958 and won 1 game with Starr, Taylor, Hornung, Ringo, Kramer, Gregg, Nitschke, Currie, Forrester, et al. Lombardi turned them into winners.
Belichek has been to 6 Championships while running the Patriots, winning 4. The list of free agent additions and subractions he's made is astonishing (
http://www.nepatriotsdraft.com/patriots-free-agency-history), and includes Rodney Harrison, Rob Ninkovich, Mike Vrabel, Junior Seau, Danny Woodhead and a bunch of "over the hill" vets that played well for New England for a year. AND he averages 8-9 draft picks yearly. So, if Championships are the goal, maybe the Patriot way ought to be the model(minus the cheating, of course).
McCarthy has had an excellent run over the last 7 years. Had his teams won a couple more Championships he'd be considered among the best coaches of all time. But he hasn't. Those of us pushing 70 are getting impatient.