First time posting, never felt a need to add to any of the comments that were already on a story, but for this one I registered.

Joe F did point out some of the more unknown things that happen behind the scenes. Just because it is a sunny day at your airport, bad weather or even the chance of bad weather over the route to take, your destination, your alternate airport, (nobody thinks of what the weather could be at the alternate emergency diversion airports is likely to be, ala Mr. iPhone) can play a major part in the delays and planning of flights. High/Low pressure systems can cause severe wind shear with little or no notice at certain times. No cloud cover, sure, but the wind is a harsh thing at times, even at the "calmer" altitudes. Bad headwinds eats into your fuel, possibly cutting you too close to your emergency reserve for a divert should something be wrong at your destination, or should something mechanical happen in-flight. Commerical flight planning is all about eliminating that last 1% of chance for something to go wrong. They've already got the other 99% taken care of. They do not go "beating storms" into airports with major aircraft. It's called "scud-running", and is very much frowned upon in the professional flying circles. Especially with passengers involved.

Also, in regards to the "it's airline policy to only go IFR, and no VFR flights at all" comment. Class A airspace (the space that every commercial flight flies thru, and is controlled/monitored via central ATC, rather than local airport ATC) is strictly IFR, per FAA regs. If you can't file an IFR flight plan, you don't get to fly in Class A airspace. Not flying that high would just expose the aircraft to much more weather effects, making the problem worse, not to mention routing a commerical jet around all the little airports and city/military airspaces between point A and point B. There is no pilot decision to switch a flight to VFR just because IFR is grounded for a major airline flight. The mere idea of switching to VFR flight rules because IFR approaches are congested is laughable at best. VFR would require even more from ATC, and the really big, major airports, tend to shunt VFR off to the side until they get a slot open. They pretty much request that you fly only IFR into the airspace, to make it all go a whole lot easier. IIRC, DFW, LAX, LaGuardia, Seattle, O'Hare, Miami, are all strictly IFR. They have you slotted from at least 15 miles out, as far as when you are landing, which runway they are going to put you on, who they need to keep in the pattern to let craft off of the ground, etc.

If the poster got a free voucher because of the VFR/IFR arguement, they gave it to him just because they knew it would be quicker and easier to just give the guy a free ticket than to try to get the info across to him. Once you have an annoyed/annoying guest at your ticket counter, you just do what you need to do to get him away. Maybe that's the trick to it, rather than anything truly scientific.

Just don't think that pulling up weather.com and putting your destination in, and seeing that it's 60 degrees and sunny the last time it was updated means diddly squat. Sorry for the ramble, just felt the need to share.