Pre-sale IS a promise of ROI. Otherwise, why would anyone buy a pre-sale that will go down 10x on launch? Or I'm missing the basic math here again?
A presale can be made with a promise of ROI. We have made no such promise. We are simply selling part of the tokens prior to launch as a way to potentially fund, and speed up the development of the ecosystem along with offering a way for people to get their hands on it without requiring to mine. The tokens are used to pay transaction fees. If it goes up or down is related to how much the blockchain itself is used or not in the future.
This is related to future user growth, how many other assets are implemented on top, and is not promised to happen.