Plenty of people in the travel industry are underwhelmed about the seeming lack of market clout of Google Flight Search and Google Hotel Finder, but to Jeremy Wertheimer, vice president of engineering at Google Travel, the “rates of change” are all just fine.

Wertheimer, who co-founded flight shopping and pricing engine ITA Software in the early 1990s and sold it to Google as the basis for Google Flights for $700 million in 2011, is unfazed by the criticism, and speaking at the PhoCusWright conference in Hollywood, Florida, today, he argues that critics are just viewing the “iceberg.”

Wertheimer said that to develop a good travel shopping experience, you need lots of data and to “build things. Building things takes time.”

Displaying his computer scientist’s bent, Wertheimer adds: “To me, as long as the rates of change are going in the right direction, it’s a matter of time.”

Google obviously has plenty of time, and is no hurry to set the travel world on fire. Wertheimer has plenty of patience.

PhoCusWright moderator Douglas Quinby asked Wertheimer about gaps in Google Flights’  international capabiles.

Wertheimer, who built the ITA Software business in Cambridge, Massachusetts, which borders in-your-face Boston, continued to answer Quinby’s inquiries with stereotypical California cool.

Quinby had noted that a Google blog post conceded that there are gaps in Google Flilghts’ international prowess.

“There are gaps that get closed all the time,” said a nonplussed Wertheimer. “We don’t do a blog post when we fill gaps.”

He atrributed the gaps in Google Flights on the international front to being mostly about “working with partners.”

On the hotel front, Wertheimer said Google Hotel Finder, which like Google Flights is a metasearch product that competes with Kayak, TripAdvisor and others, “on the whole we are pretty happy about how things are going.”

Asked about the fact that companies such as TripAdvisor, and perhaps Kayak, terminated or may terminate their contracts to use ITA Software’s QPX flight shopping and pricing product, Wertheimer said: “As things go, some relationships come, some relationships go.”

The crowd at PhoCusWright wasn’t impressed. The Twitter stream for the event, which is typically supportive of presenters, turned on Wertheimer:

Despite the criticism, Wertheimer and Google Travel has fewer concerns than many of the startups and technology firms at the conference. The search giant has all the time in the world, and plenty of human and computer power, to get it right when it is good and ready.

Photo Credit: Still from a PhoCusWright interview with Jeremy Wertheimer in August 2012. PhoCusWright / YouTube