They argue that’s because it’s A): cheaper B): more secure and C): frees up internal engineers to do more valuable work like write better software to run on AWS. Google’s (GOOG) enterprise chief Diane Greene recently made similar arguments. Microsoft (MSFT), the third major public cloud player, is less strident about everything-moving-to-public-cloud since many of its customers also run Microsoft software in their internal data centers.

Jason Forrester begs to differ with Amazon’s take. Forrester, formerly global data center network manager at Apple (AAPL) who also spent more than 10 years at IBM (IBM), says reports of the death of corporate data centers are not just exaggerated—they are flat-out wrong.

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Forrester and much of his infrastructure team left Apple last year to create SnapRoute to prove it. This Palo Alto, Calif.-based startup aims to bring the same sort of networking flexibility that public clouds claim to corporate data centers running important business applications. Facebook described some of SnapRoute’s work in a blog post, but this is the first time Forrester has spoken publicly about SnapRoute’s plans.

In Forrester’s view, it makes sense to rely on public clouds for what he calls the “easy stuff”—email, web apps, and other applications that are not time sensitive. But the real differentiating, strategic applications like Apple’s virtual assistant Siri, Apple TV, Uber’s mapping service that tells your driver where you are and vice versa run on internally owned and operated data centers. And he thinks they will continue to do so, despite the best efforts of public cloud purveyors to convince us otherwise.

“Most enterprise applications are highly customized for the company’s needs, which means they don’t fit neatly into the public cloud mold,” he noted. That’s why most companies’ big accounting and inventory tracking systems aren’t on a public cloud, he said. When it comes to their money-maker software, companies need “complete command and control of their infrastructure,” he noted, adding dryly that “It’s hard to have that command and control if you can’t even tour your public cloud data center.”

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Forrester’s view is very controversial in this day and age, where even big security-obsessed banks are starting to talk openly about using public cloud. But if you really scratch the surface, hardly anyone says they’re offloading everything to a public cloud.

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One reason that companies feel better about keeping applications in-house is that the cost of the no-name server, storage, and networking hardware is much less than the old brand-name products that companies used to buy from HP (HPE), IBM (IBM), Cisco (CSCO), and EMC (EMC). That’s largely due to the Facebook (FB)-backed Open Compute Project, which helped design specifications for data center hardware that anyone can use.

“All of this commodity hardware was once reserved for the big guys but has trickled down to everyone else,” Forrester said.

After they’re on cheaper hardware, they need software that will let them reprogram and configure that hardware as needed, on the fly. SnapRoute is attacking that problem on the networking side with software called FlexSwitch, the technology that it will contribute to the Open Compute Project for others to use.

Nicira, now part of VMware, (VMW) was early entrant in this space, typically called software-defined networking. But Nicira was all about managing old-school hardware from many vendors while SnapRoute aims to manage all that inexpensive, unbranded network gear that companies are buying now.f

Public cloud advocates often joke that traditional tech execs are “server huggers” because they just can’t let go. “I’ve tried hugging a lot of servers and believe me, they don’t hug you back,” AWS chief technology officer Werner Vogels has quipped.

Maybe not, but SnapRoute’s take is that there are serious reasons companies will need to hold onto their servers—and their own data centers—for a long, long time.