A simple Middle Man if he succeed to attack the platform, he may adhust parameters orders of users to sell or buy at exact point (price). He may sold his coins high or buy coins sheap (am just imagining a possible scenario) as the platform may contain data of users that may be also get hacked. The point here is about securing the platform against any possible bad case so the add to GitHub would be the right next step.
Just to make sure we talk about the same thing, you mean a man in the middle attack right? This scenario would mean someone infiltrates the connection between you and our service which would be able to happen if you have a virus infested computer (we can not control that) or your internet provider manipulates the connection (extremely unlikely). As you see our website is SSL secured so all connections are already encrypted.
Even if someone were to gain access to your exchange account through us what is the value in selling all your coins for cheap (which wouldn't happen since you can't sell below market value)?
Releasing source code on Github does not make anything more secure, it simply allows people to read the source code. If they find something vulnerable in it it would be up to them to tell us or in fact maliciously make use of said vulnerability. As mentioned this is a cloud service and we aim to provide it in a monthly subscription, therefore releasing code for everyone to freely use is not "the right next step"