You people are idiots. Meb won for 3 reasons: 1. The field sucked today. 2. The field made tactical errors. 3. Meb is way better than you think, especially on hard courses.
1. The top tow guys in the field, on paper, aside from Meb, were Dennis Kimetto, Lelisa Desisa, Ryan Hall, Marcos Geneti, Gebre Gebremariam, Tilahun Regassa, and Wilson Chebet. Kimetto couldn't even run a half marathon at Meb's full marathon winning pace a month ago under ideal conditions. Lelisa Desisa is very overrated. His PR of 2:04:45 is from Dubai. Dubai will run a little shorter than other major marathons due to the straight course, and the lack of hills and turns, coupled with ideal weather, helps people to not blow up. Other than Dubai, he has run 2:10 in Boston to beat possibly the weakest field they've ever assembled. Chebet has run mid-high 2:05s on some fast courses, but hasn't beaten a top level field. Hall was obviously not even close to in shape. Geneti is another guy that's fast on paper, but only because he ran his time in Dubai. Gebremariam hasn't broken 2:08 except at the wind-aided Boston. Regassa may have been the most sure thing in the field, aside from Desisa, but he's very unproven on hilly courses. Overall, this field seemed strong on paper, but was actually pretty weak. Meb is a consistent performer and he managed to take the win on a day when the only guy that definitely should've had no trouble in beating him handily (Kipsang) was far from peak form.
2. The field made massive tactical errors. Letting Meb and Josphat go was stupid, but they probably just figured he was an aging 2:09 guy unlikely to even break 2:10 at this point that wanted his moment in the spotlight and didn't worry about him. By the time they realized that he wasn't going to blow up, it was too late. Chebet was almost able to close the gap, but he screwed up badly. He cut his splits down way way way too fast. The ideal situation for him would've been to catch up at mile 25.5 with something left in the tank, but he cut into Meb's lead heavily over just a few miles while Meb was running well under 5:00 pace, and this destroyed his chances. By the time he caught up, he was completely gassed.
3. Meb is only a 2:08 guy because he hasn't run a course like Chicago or London since figuring out how to race the marathon. He ran Chicago in his second marathon (2:10 PR, after a 2:12 debut), and only ran London when injured (DNF). Meb historically does very well on hard courses with a lot of hills, and that's how he won Boston. I hope he runs Chicago this fall to hit a solid PR (2:07:xx, maybe even 2:06:xx?), but I'm guessing NYC will pay more, so he'll go run another 2:09-2:11. Either way, those races will have better fields and he won't win, but he'll run another consistent race.