Actually, I do host everything privately and only connect to it from trusted machines over encrypted channels. But I'm far from typical in regards to preferring my own clouds over popular trusted resources.
For what it's worth, I think the level of criticism you're receiving is grossly unfair. However I also don't think you've done yourself any favours here either. You content has been focused on how "cool" this technology is without really focusing on the security of your service. Since this is a hacker forum and since the very nature of SSH is a secure communications channel, it's understandable that people are concerned about this aspect of your business.
However I also think people have gone overboard. This is a typical example of a growing trend on HN for members to dismiss others hard work - after all, it's easier to contribute in a community by offering negative criticism than it is to create content for all to criticise.
Sadly though, even in spite of my issues with the direction this thread has taken and the amount of negativity posted, I do have to agree with the points being raised. So as much as this project interests me and looks innovative, personally I would rather stick with native client running locally. I don't feel you're trying to solve a problem that doesn't exist (sessions can be restored via terminal multiplexers such as screen and tmux and there are already a number of native client terminal emulators available for every OS imaginable). In effect, what you've done is created a product that raises security concerns without offering any real benefits. And it really pains me to say this given my previous rant about the amount of negativity in this thread.
Best of luck though.