Cool idea though.
The scamming that happens to homebuyers is not even comparable to the risk in uploading docs to a website which promises they won't share user data with anyone. This is genuinely a pro buyer tool with no association with any 3rd party.
The tool has already helped many people negotiate and get a better deal on their mortgage. Please before judging understand that 70% of buyers overpay in their mortgage 1-3% in closing costs and bad rates. It's mind boggling how much lenders get away with profiting in junk fees from stressed out homebuyers.
I have no reason to think you're not completely sincere in this!
But, realize it doesn't mean anything.
Unless that promise is backed by some ironclad contract, it means nothing. Companies grow and hire new people who don't care about the original values. Or they get acquired and all bets are off. Or they start running low on cash and suddenly decide monetizing all that data is a good idea after all. Or it becomes visible enough to attract attention of the government who shows up demanding copies of data. And so on.
I've been in one or more startups where all of these things have happened.