The only BIG Negative is : The investment has to be made by the people applying for the visa.
It feels like there could be some workarounds here. They explicitly say the money can't be from a loan, so that idea is out.
But I've read of other techies getting an E2 for an investment just in the mid 5 figures range, so it mightn't need to go into the 6 figure range after all. Especially with a profitable software business where the profit margins are extremely high and the running costs are extremely low, I think they would lower the threshold.
If you move to the US and get funding from a US VC / Angle then I think it gets tricky because it says : At least 50% of the investors must be nationals of the treaty country.