By the same token, he couldn't mention the real reason. An oppressed Special Level Mecha warrior would inevitably incite anger among these people, something not conducive to unity.
The same goes for the Nerve Link Technology. If he were to admit using it, there'd surely be those who would see his idea as a waste of resources. He didn't want to argue with anyone or explain that even without the Nerve Link Technology, his Mecha piloting skills were still formidable.
Besides, he thought he might potentially use the Nerve Link Technology; it's just a possibility.
Without any evidence, he couldn't convince anyone at the moment, arguing and refuting would only be a waste of time and energy.