Battery life can be overcome by the SP3 but the Mac can't overcome the fact it can't run apps like the SP3 can. If all I needed from my computer was email & Internet browsing, I would probably use a Mac.
Since I do a lot more on my Macs than email and internet browsing, I will disagree with your assessment.
Word processing, spreadsheets, music engraving, video and audio projects and a slew of others. For some even using MS applications to do it. And if there is something I just have to have Windows for, I can throw it up on my Mac.
But I tinker with this stuff, so in addition to great Apple gear, I've got great Windows gear. Currently an HP AIO desktop and a Lenovo Yoga 2 Pro (i7/8Gb/256Gb). In addition an iPad Air 2, MacBook Pro Retina and an iPhone 6+.
Love 'em all for differing reasons and uses.