JRiver stands to lose out on revenue due to people not installing it because of this false positive. As the manufacturer, I'd think it in your best interest to take the bull by the horns in regards to making sure your software is not reported by reputable and widely used vendors as a virus.
Also, this is not per se a Trend problem. Based on the information above, it is not picking up MC as a virus, rather it is exhibiting virus like behavior. Their Heuristics engine watches for certain behavior, and tags it as suspect, even if there is no current virus signature attached to it. This is done to protect against zero day viruses and such. There may be issues with how the install is making calls, that cause this problem, and Trend may advise you on how you can fix... Or, Trend could add you to a whitelist of sorts..
Regardless, JRiver should want to make it as convenient as possible for customers, and future customers, to install their software...
It's not like Trend isn't a popular virus scanning program.