I don't think the current Celtics have that same desire to win that the Celtics of old had. Perkins was highly critical of Stevens defeatist remarks.
The team hasn't won a title in 13 years. There was a time when the Celtics were EXPECTED to win. They were the Yankees of the NBA. But that was a different ownership and different management. The current one seems content with the status quo.
The mindset of being "expected" to win is toxic for fans and players alike imo.
Celtics exceptionalism is tiresome and promotes fan negativity. Calling back to a time when the Celtics were the "Yankees" of the NBA overlooks the reasons why the Celtics were able to be so exceptional in that era, and how drastically the league has changed since.
Witness the fact that the Celtics have been a very successful NBA franchise by really any metric (including titles) in the last 20 years, and yet a lot of Boston area fans seem to regard them as a disappointment.
This is a sport where any given era is dominated by just a handful of players. It's a league that increasingly is giving those players freedom to go where they want, which inevitably privileges teams in big cities where young stars want to live. The Celtics don't have one of those "marquee" players, and they haven't had one for decades now. You could argue KG was one, but when he was on the Celtics he was already a bit past the point where he was part of that group.
The point being that the expectation that the Celtics are going to compete for and win titles on a regular basis is just not realistic. There are just a few franchises in the NBA that have the advantages needed to consistently manufacture the circumstances necessary for that.
For every other team, you need luck, good ownership, great management, and good to great coaching to have sustained success, and that sustained success still won't give you better than an outside shot at a title. The Celtics have had all of those things except for the luck part (although they've had their share of luck here and there, e.g. winning the Tatum lottery).
Be thankful for what you have and don't relinquish hope for the future. That's a recipe for enjoyment as a fan, in my opinion. Not "expecting" the team to win titles.