My problem with Ainge's comments are that he's probably right, which makes this kind of a "bad" contract.
The NBA has a very restrictive salary structure that really favors teams over players and in a way is very conducive to super teams and anti competitive balance.
The first major problem is Max Contracts. Gone over this before, but there are many annoying things about max contracts. First, it makes talking about salaries annoying. The max is set, but who is worth the max? Well clearly Lebron and Durant are worth the max. But then we get into all these discussion about "player X isn't worth the max, he's worse than Lebron!" But the problem, clearly, is that Lebron is, in basketball terms, worth probably 2 times the max. So it's not the Randolphs, etc. who are overpaid, it's James/Durant who are underpaid. Now, in terms of competitive balance, because of the cap, it makes it possible for 2-3 James/Durant level players to be on the same team, which would be impossible in a Team Salary Cap but Individual Salary Free Market System.
The second wrinkle is the extremely restrictive and relatively lengthy rookie contract scale. Absolutely controlled for 4 years, and semi-controlled for a 5th. This frequently locks in great players at prices insanely below market value.
So the above points are key in understanding why I think Green's "Fair Value" contract is a bad contract.
My reasoning:
1. There is a finite amount you can spend on players (i.e. the cap) and money spent on one player is money unavailable for another.
2. Contracts are guaranteed, both ways.
3. There is an individual max contract
4. There are set rookie salaries
5. Because of 2, 3, and 4, you have to find certain kinds of "Value" to gain a competitive advantage and build a winning team. These values are:
Tier 1: Franchise Changing:
a. Elite player underpaid on a Max Deal (James, Durant, George, Harden, Paul, etc.)
b. Great players who are good really quickly, thus the team could conceivably contend while the player is on a rookie deal (George recently, Rose recently, Anthony Davis (but the team sucks).
Tier 2: Great Deals:
a. Borderline max players who lock in below max value (Rondo, Milsap, Horford, Noah)
b. Mid to upper-level players who lock in at barely above solid rookie deals to just above midlevel deals; Sometimes 1 year deals for ring chasers/value boosters (Tony Allen, Perkins' first extension, Posey, House, Conley)
c. Solid rookies who contribute like mid-level guys but are controlled, so easy to fit onto a packed contender (Kawai Leonard, Taj Gibson pre-extension, Jimmy Butler)
Tier 3: Fair Value:
a. Borderline max guys who sign for the max (David Lee)
b. Known non-max guys who sign for close to double figures, about their "market" value (Ibaka, Green)
c. Journeymen established true role players who sign for fair value at or below MLE deals and/or useful rookies who enter the leauge about appropriately paid (Korver/Dudley types).
Tier 4: Consensus overpaid:
Guys like Rudy Gay
Tier 5: Apocalyptic:
Perkins now, Amare, etc.
So when building a great team, you really want to be working in Tier 1, Tier 2, and supplement it with tier 3(c). Once you start adding in too many tier 3(a), tier 3(b) players, it just takes up too much capspace to build good teams without a ton of luck. End up with tier 4+5 players, and you should probably actively try to dump and rebuild. With tier 3(a)/3(b) players, unless you are actively contending you probably should get future assets for such a player if you can. (you could argue that Ray Allen in '08 was a tier 3(a), but with KG/Pierce tier 1(a), Rondo tier 1(b), and Perk tier 2(b), Posey/House/Cassell tier 2(b) or 3(c), and even Powe/Davis as tier 2(c). So it was an overwhelmingly underpaid team (even pierce and KG were underpaid, because of the artificial max constraints) that could therefore make up for Allen's "fair value" deal).
So that's my thoughts of how a "fair" contract can end up being detrimental to competing for a title, because most title teams are working in various portions of the "underpaid" tiers without many highly-but-fairly-paid guys.