Is there anything to the “disrespect” thing?

It's a question I had when NBA.com allowed me to ask something of Doug Collins.

We keep hearing about teams feeling disrespected and using that as
motivation. The Celtics just beat the Cavs in a series where no one was
picking them at all. Is the notion of teams effectively using
disrespect as motivation legitimate… or is this just something fans
believe but isn't really true?

DC: In all my years
around it, I've never seen a team that says, "Hey we're going to show
you what we're all about." I think Doc Rivers ?did such an incredible
job all year long, because if you read is stuff during the season, he
said, "I like my team. – The big thing is: Can we get healthy? Can we
get everyone ready to go come playoff time?" They lost games during the
regular season because Doc aired on the side of "I'm going to be
patient, I'm going to be cautious, we're going to cut back on practice
time, so we can be ready to go in the NBA playoffs." The Lakers have
done the same things this year- 57 wins; a lot of people say they may
have won 70. Phil Jackson navigated the landscape. You saw that Gregg
Popovich did the same thing with an older team in San Antonio.So
when I look at things, this disrespect thing, you know it's easy to
throw out there that they've got a chip on their shoulder,
this-that-whatever, but I think what beats in those type of guys' chest
is a competitive heart of a champion. That is really what the motivating
factor is. And if Boston is healthy, and I talked about this the other
day a little bit: If you took the Boston/Cleveland series and if you're
going to choose up sides and you had to choose teams, how many guys
would you pick off Cleveland, and how many would you take off of Boston?
Arguably you'd take LeBron with the first pick, but then you would take
five Celtics starters as your next 5 picks.

They got a couple of guys from a couple of sites representing all of the playoff teams… so there are a lot of good questions in there.  Worth checking out.