We were worried that Microsoft might wind up with frenemies in the PC industry after introducing its Surface tablets. There hasn't been a lot of backlash so far, but the Windows 8 tablets clearly rankled some Acer executives -- they're lashing out at their OS partner in a very public fashion. Acer's EMEA senior VP Oliver Ahrens is accusing Microsoft of trying to copy Apple's business model and thinks the Surface line will struggle to get any traction. It could lead to a "defocus" at Microsoft as the software giant forgets the PC builders that got it to the top, he says. Meanwhile, frequently outspoken company founder Stan Shih isn't even convinced that Microsoft is serious about the whole affair. To him, Surface is just an attempt to spur tablet designers into action that will fade away if and when Microsoft deems it a success. It's entirely possible that either executive is right knowing Microsoft's very mixed track record in hardware. Just consider the source before you cast too much doubt of your own: Acer isn't exactly great with tablet market predictions.