All this time, Gai is actually the one who created Raidrisers, and he ordered "Naki" (The 4th member of MetsubouJinrai.net) to use it on humans.Raidrisers use by the general populace.....he is creating an army!!! For world domination!!!!
And imagine if Gai keeps the threat of MetsubouJinrai.net rising, people and government will demand a solution like a weapon to destroy MetsubouJinrai.net, most likely all of them will demand weapons development from Zaia Enterprise. This is why Gai manipulate MetsubouJinrai.net and Ark!
Not just that, people will also view HumaGear as a "killing machine" forever if that happen.