Shock horror, priority was given to the msot technologically advanced railway in the UK, dedicated for high speed European services and fast commuter trains. I have a sneaky feeling that they did similar things at Heathrow. They totally disgregarded flights to Edinburgh, Birmingham and the Isle of Man in favour of those lah-di-dah continental flights!
In terms of passenger numbers, who are the main users of St. Pancras? I'd wager that between EMT, FCC and SET, international travelers are very much secondary. Yet the design of the station is geared towards Eurostar at the expense of all others. If you want to mention Heathrow, let's not forget that T5 has lead to less crowding at the other terminals, resulting in an improved experience for all, whereas St. Pancras has resulted in a poorer experience for MML travelers.
Hmm, where's Eustons magnificent archway again? Smashed to pieces. Yes, I wish they'd just destroyed the trainshed at St Pancras as soon as they decided Eurostars terminal building had to be nice, as it was what welcomed foreign travellers to London. We should have just built a six track box for them and left the grand old building for the domestic traffic with their lovely period 25Kv catenary, just how the Midland Railway would have wanted. I believe we call it progress and generally progress helps to make our lives better. St Pancras no longer has anywhere for a horse and cart to pull up, but that's because it doesn't need to. The MML is probably (and this will cause some debating) at the very best, the fifth most important line in to London after HS1, WCML, ECML and GWML (not necessarilly in that order) so why should it be treated as the jewel of the crown?
I did describe Euston as a "monstrosity"! It definitely wins no awards for aesthetics or heritage, but if you want to
catch a train it's certianly more functional than St. Pancras.
E.g. Say I have a few minutes to wait and I want to grab a bite to eat. At Euston I can grab something from Burger King on the main concourse, while at St. Pancras I have to wander around what is basically a shopping centre vainly looking for something that isn't a sushi restaurant, champagne bar or coffee house and probably end up having to spend twice as much.
That's not to mention the "long drag" that is getting from the tube to the MML platforms with luggage or the even worse siting of the SET platforms. Oh, and how the great arch seems to magnify the screech of Eurostar mechanical brakes or the general state (both inside and outside) of those 15+ year old trains...
I saw the "800 million pound station" documentary, quite interesting really, but it was clear that the designers of the station had lost sight of the fact that they were designing a
railway station, i.e. a place to catch trains. They were constantly talking about how they wanted to design a "destination station" with gimmicks like the "world's longest champagne bar" (what are they going to do when someone builds a longer one? turn all the seats 90 degrees and call it the world's widest?), as if people would go there with no intention of catching a train! (Enthusiasts excepted of course!)