Microsoft's OEM (original equipment manufacturers) partners have been just as bearish on Windows RT as IDC. In January, Samsung -- a key tablet maker -- said it wouldn't release a Windows RT device in the U.S. And earlier this month, the South Korean electronics giant confirmed it was pulling its Windows RT-powered Ativ Tab from European sales channels.
Mainelli stopped short of saying Windows RT was a flop -- "It's not a bad product," he argued -- but said it was clear Microsoft made the wrong design choice, then followed with muddied marketing.
"There's a reason why Apple scaled iOS from the phone to the tablet, why Google scaled Android from the phone to the tablet," said Mainelli. "That makes a lot of sense, there are synergies there."
Microsoft famously decided on a different path, instead taking a subset of its Windows desktop operating system, porting it to the ARM processor architecture, and calling it Windows RT.
"Consumers aren't buying Windows RT's value proposition, and long term we think Microsoft and its partners would be better served by focusing their attention on improving Windows 8," said Mainelli in a Tuesday statement accompanying its revised tablet forecast. "Such a focus could drive better share growth in the tablet category down the road."
He elaborated in the interview.
"As new processors come along, Microsoft should make a big push that Windows 8 is its tablet OS," said Mainelli. "That has the potential to have legs."
But Microsoft could take another tack, Mainelli acknowledged, citing the quick shift in tablets to devices with screens 8-in. or smaller. This quarter, more than half of all tablets shipped will be of that size.
"We may see Windows RT shifted to tablets of smaller sizes and lower prices," Mainelli speculated.