People buy MacBooks for many reasons. The prices have significantly gone down the past few years, making them much better deals. Build quality of the recent models is exemplary. The MacBooks have a nice clean intake and exhaust system avoiding the usual design on the bottom of a laptop case which is filled with vents. Oh, and the battery life of the MacBook and MacBook Pro are both at 10 hours. Okay, in the real world it is more like 7:48 minutes according to Laptop Magazine's review of the 13.3" MacBook Pro. The MacBook's battery advantage extends beyond the ability to provide all day computing, it also goes into its durability. The typical lithium ion battery can last 300-500 discharge cycles and is good for 2-3 years. Newer lithium ion batteries can last longer. Apple designs its batteries to last a full 1,000 discharges and to last 4-5 years. If you plan to replace your laptop every year or two, this might not be that big a deal. Also, the newer Intel i3/i5/i7 laptops with a decent-sized six-cell battery (6000 mAH) provide more or less 5-6 hours battery life.
If you decide the premium price for having an Apple on your lid is worth it, it is good to know that there is a lot of substance under the hood too.