There was a reason why he said it was a gamble .
Plus no one die so his gamble paid off .
Akainu would have made the marines come out looking good which is what fuji did not want to happen .
First off, you're saying that no one died as a result of bird cage? They all got out of the way? I find that...unlikely. Or atleast symptomatic of a problem with OP as a manga in how it portrays the effects of violence, but that's another topic.
Still, you're really not making him look like any less of a tool. "Oh, don't worry, I was only willing to risk all your lives on a coin flip. Lucky it turned out the way it did, or else you'd all be dead, hahaha."
It seems that every senior marine knew about the situation on Dressrosa and just stayed away. In fact Fujitora was the only one willing to do anything at all. Remember that the marines were not told that it was a trick when Doffy left the warlords. Fujitora went there before he got his protection back but was presented with a "bait and switch" where he was told to arrest Law instead of Doffy.
I think that Fujitora was furious the whole time about being manipulated. So in this chapter we see the difference between the anger of a tiger and the anger of a dog.
If Riku raged at Fujitora as if he was the mastermind behind the state of Dressrosa it would be pretty low. The marines saved a lot of people under his orders.
It still doesn't change that Fujitora played along and allowed the people of his kingdom to die, or risk dying. It's weak logic that because Fujitora was manipulated into taking a detour and had his desired target (Doflamingo) snatched out from under him, that justifies him playing hot potato with thousands of innocent lives.
It's been only a few years since the Alabasta incident. How many countries and incidents like dressrosa and alabasta have there been with the government creating or abiding oppression? How many cases of the WG claiming glory for itself like in Alabasta? How many cases like with Tom's workers and the straw hats in water 7 where cipher Pol and the government attack civilians and blame it on someone else? How many cases like ennies lobby where the government burns
down an island and blames it on pirates? How many cases like marineford where the WG convinces the masses that a pirate will sell out his own allies? How many Oharas get too close to the sun and are destroyed?
The WG as an institution has been spinning the truth and deceiving the public for centuries, the best way to expose it is to broadcast it to the world, not by giving it a shred of credibility that it will spin into complete moral righteousness to the masses.
I think you're projecting a bit. Fujitora only wants to eliminate the warlords. He said nothing about that other stuff. Though I don't doubt that he would disagree with it, he's only actively against the warlords and has not made any statement on the other atrocities the WG has committed. Hell, he might not even be that against it, since he's apparently okay with putting thousands of people at risk for an agenda, as long as it's on the government terms.
But I think all of you are missing my point. I'm not arguing that the Warlords are a shitty system and Fujitora is right to want to abolish it.
I'm just pointing out that, in the best case scenerio of this situation, he was willing to allow thousands of people to be slaughtered for that agenda. If King Riku understands this, I don't find his reaction at all believable if he cares about his people. He'd agree, the Warlords have to go. But I don't think he'd consent to having his people slaughtered in order to make that happen. As a king who cares about his people, he ought to be furious at such callous endangerment of his people for his political gains, even if he agrees with the goal of those gains.