Hmmm, a trifle partisan on the side of Edinburgh eh V12?
Well, in the words of Samuel L Jackson, allow me to retort:
One the 5 'good reasons' you mention, only one holds any water, and that is cost - but we will come back to that.
Speed - are you telling me it takes less time to drive (or for a real laugh, take public transport) to Edinburgh, park, get through security and the wonderful shopping experience, then walk half a mile or so to the gate than it does to make your way - even by walking - from Dundee city centre to the airport? Hmmm.
Convenience - you really haven't thought this through have you? I tried recently to get from Dundee to Edinburgh Airport using public transport. Maybe it can be done in less than two or three hours and maybe it doesn't involve changing trains or getting remote park & ride buses, but I couldn't find out how.
Proper aircraft - you try landing a 737 or A320 at Dundee and then come and talk about proper aircraft. Wipe the egg off your face first though.
Frequency - if you are going to the capital for the business day, how often do you need to get up and down during that day? I would suggest 'in the morning' and 'in the evening' pretty much fits the bill, eh?
And finally we come to cost. Yes, cheaper fares can be found, and unfortunately that is what sways a lot of people. However look a bit deeper. Parking at Dundee - £5.70 a day, Edinburgh - £27.99 for comparable convenience i.e. without taking a bus to the car park. And then the cost of the two or three hour trip getting from Dundee to Edinburgh.....and back....
At the other end only London City offers significant advantages over any of the others mentioned, however changes to their charging structures have effectively forced out smaller aircraft i.e. ones capable of operating from Dundee.
So you see it's not so straightforward is it? And when it comes down to it, I can't think of anything I'd rather see taxpayers' (my) money spent on in Dundee right now!
Oh, and anything that means I get to avoid the 'wonderful customer experience' that is Edinburgh Airport is just fine by me.