The reference to Amy Hoy's Charm is interesting, just because that was such an interesting (and somewhat distressing scenario, if you're into RoR and Ubuntu). But to say that the Windows architecture is significantly better bang for the buck requires more of an apples to apples comparison. The best I can find is that Hoy describes Charm as having 3,800 interested users in Oct. 2012...The OP describes having hundreds…
Based on the facts above, I submit to you that there is nothing interesting about the reference to Amy Hoy's charm (and there is nothing in there to depress a rails developer using ubuntu).
As far as I am concerned, Amy Hoy's app did not get the kind of traction they envisaged simple. Hence they shut it down.
I am sure that both jitbit's app and Amy Hoy's were not as big customer wise as that form Zendesk and Salesforce. I am sure their traffic numbers wasn't anything near what zendesk and desk.com does.