Ray.... all three of my marathons were 10-15 slower than projected times... times I honestly felt at the time I could have done. So, while I sympathize with you over not meeting your ultimate goal of setting a PR, "silly" is certainly not how I would describe your effort. I'd consider it a solid effort, and in view of the race strategy foo-foo I'm going to bust your butt about shortly, I consider it a gusty effort to fight for the respectible time you did get, which netted you some impressive hardware.
"I only drank 3 times in the first 15 miles and in later miles, I hit every water stop. I ate no gel even though I had some with me".
I'm sorry Ray, but I can't believe you of all people made this rookie mistake!!
Geez, man? What were you thinkin? I'd have to agree that most of the time you lost can be directly attributed to this. I've read that even the most well trained body can only store enough calories in glycogen to cover 20 miles or so. You let the tank run dry!
Your early water stop pattern may not have been quite as big a crime, but you might have done better with water every 20-30 minutes from the beginning. You can't take in as much fluid as you sweat out during a marathon, so once you get behind the 8-ball you stay there.. Dehydration may well have been a factor too. Geez!
A few more longer, LT based runs might have helped some, but I'm not so sure about longer or more long runs. Didn't you get up around 3:20-3:30 (goal marathon time) a coupole times? I don't know that I would be driven do much more than that, unless it just happened to come (relatively) easy on a partiular day. Pushing long runs to or beyond exhaustion make it difficult get full benefit from your other quality work during the week (and invites injury).
If you can stay healthy, and not get too overzealous with future training, I think it's clear you can run a better time with some adjustments/corrections. In the meantime, BQ's do not come a dime a dozen. Any time one does that, it has to be considered a credible effort!