I disclosed my association with Airtreks.com partly as part of the basis of my expertise in the field, knowledge and partly because some might see it as a conflict of interest. If you want to disregard what I say for that reason, you are of course free to do so.
However, Airtreks.com is not and has never been a competitor of ITA Software. ITA Software is a b2b provider of services for other travel companies; Airtreks.com has deployed its proprietary technology solely for its own use, rather than (to date) licensing it to any third parties. Airtreks.com focuses on integrating unpublished (consolidator) prices from multiple sources; ITA Software focuses on published fares, or at most on consolidator prices from a single source. Airtreks.com focuses exclusively on complex international journeys optimally priced as multiple tickets; ITA Software's priority is the simplest domestic journeys that can be priced as a single ticket. Basically, Airtreks.com targets and has optimized its systems for the niche furthest from ITA Software's core market.
Some companies license services from ITA Software (for domestic prices and tickets) and also are affiliates of Airtreks.com (for complex international journeys), just as Sabre for a time offered a co-branded version of Airtreks' service to its subscriber travel agencies, alongside its own pricing tools (which like those of ITA software are optimized for single-ticket domestic published fare pricing).