Because he is NOT suicidal....
Simply because Hisoka has never challenged anyone that are physically stronger than him despite the fact of it's availability. i.e. Uvogin, Franklin, Silva and Biscuit. People who's raw power are way above his. Therefore his attacks are meaningless unless he has more than just bungee gum in his arsenal. Razor has the same build as the characters I mentioned, and is capable of destructive power well above Hisoka's defenses as well(Shown in their volleyball game). Meaning Hisoka does not have the ability YET to pierce through their defenses, unless he has an extremely hax ability.
Rationale: His fight with these people would look the same as Uvogin's and Kurapica's. Unless he has an ability like Chain Jail, there is just no way he could harm them, because they are physically and nen wise more powerful than he is. If he is stronger or atleast at the same level, then that volleyball(not full power) catch wouldn't have broken his fingers. Imagine what Uvogin's fist would do.
Silva - Hisoka can pay the assassin to kill him, and we have a fight.
Buscuit - A dozen opportunities and he does not take it.
Razor - He could've attacked him on the spot after the game.
Franklin - a simple duel between teammates
Uvogin - same reason as Franklin
My thoughts are that Hisoka targets potentially cerebral fights, i.e. people who could give him that must not have that much overwhelming power Chrollo, Killua, Illumi, Ging and Gon.
Also, just to add. Chrollo as evidenced by his fight with the 2 main heads of the Zaoldyecks, did not show any feat basic nen wise that could pierce through Zeno's and Silva's defenses, which is why he used a specialized dagger. Which means in pure combat without Hatsus both he and Hisoka are not in Zeno's and Silva's level and therefore Razor. The only factor that both Zeno and Silva were being careful in their fight with Chrollo is that Chrollo has the advantage of many unknown abilities. Which one of them could possibly be hax, like an ability to put some1 in a cage regardless of their power. Or teleport like we've seen Chrollo did once.