I think the other goal being that if you create a profitable strategy, you can enter it into competitions, trade with other people's money, and make a profit. I think the platform is a value add, I have an account and use the research notebooks. Some day when I more spare time I'll make some trading algorithms.
It's like a slot machine tournament. No one has an edge but some percentage of people will do well enough over a finite period to convince them to put real money behind their lucky algorithm.
I don't know what you verified, but it directly contradicts my own experience and the FAQ: https://www.quantopian.com/faq#data-sources
To your second point, as another commenter said Quantopian doesn't see your algorithm unless you give them permission, as outlined in the terms of service (which are very readable, by the way).
NB: I am not unaffiliated with Quantopian and don't use the platform for my own trading, but I have tried it out before.
Oh, they can? Well that's funny, because I just went onto Quantopian and checked for myself.
Gee, would you look at that...they are there.
This took me all of five minutes. Do you have anything else I can easily disprove while I'm at it?
I'm not searching for a needle in a haystack for you. Make a falsifiable claim, and make the entire claim, with the specific dates you're talking about, or stop this astroturfing against Quantopian and QuantConnect that you're doing.