Haha, no. But I know someone who was part of the OpenTherm development.
To quote him:
OpenTherm exists because Plumbers don't trust Sparkys and Sparkys don't trust plumbers.
OpenTherm is easy to install but "stupid" as hell and not adaptable to modern needs mostly, especially if you consider modern heating concepts like passively heated houses, heat pumps,etc.
That's different from KNX (or Modbus in that regard) - They are much broader in their appeal. Singule use/walled garden systems are always a bad idea,imho.