Why not? If they invest in their own platform isn't it proving that they believe in it and the ICOs get some additional funds even if it's from the owners themselves. I think it doesn't matter who invests or not. What matters is how much funds the project raised and how well the team is utilizing the funds and whether the project is genuine or not.
well... don't they get the funds even if it fails?
a guy with alot of btc could easily artificially inflate the stats to make it look bad for others.. for example, antshares could invest 2000 btc into their own platform just to inflate stats, and then say "5000 btc raised!"