Geography i.e the landscape, or where people live, has nothing to do with the tracks not being able to cope with high speed rail. It's demand. that doesn't state why when the tracks were first built they weren't built to a higher standard.
It's all to do with the romans. Hence no grid structure in the UK. Many roads and rail lines follow old roman roads. Other countries have got over it. In Germany it very easy to get trains without going through Berlin.
Other countries mange a decent rail service. We suck compared our European neighbours. Of course they many have government owned services. We sold ours.
It is about the relative location of each city - ie, geography.
Like many countries our network is based, like it or not, around the capital city. This is not unusual - it's the same in places like France. Most large cities have very good links with London. It's a hub and spoke model. This works brilliantly for travel from major population areas into London, or from major population areas to other major population areas along the route to London but obviously if you want to travel between cities on different 'spokes' then you must rely on lines designed not to take you specifically from Birmingham to Norwich but via places in between as well.
There was absolutely nothing wrong with the standard our rail network was BUILT to. Infact, it was built to exceptionally high standards. Given that most of it was built in the 1800's and remains in use today, I'd say thats a pretty good testament to the very high standards it was originally designed to. We pioneered the railways - we brought the to the world. The downside of this is that, like most major civil engineering projects, you are often stuck with what you originally designed. Building a new network from scratch, as is the case in places like France with the TGV network, makes it far easier to end up with fit for purpose high capacity high speed rail. We can't really do that. Our population density is higher for a start, so decimating the entire country by installing loads of direct high speed rail networks including one to link Birmingham and Norwich is unreasonable. I mean just look at the whinging and moaning going on as a result of the decision to build the HS2 link? Instead we have to take a different approach - increase capacity on existing lines. This is far more difficult than most people in internet threads think, especially as it's difficult to do any sort of work without major disruption to existing travellers, again causing more internet 'trains sux' arguments.
If we had a much larger country with reams of open space we too could have a network of TGV-style dedicated high speed rail lines. There would also be more demand for such lines - given the great distances involved. But we don't, so we don't.
I don't disagree that there are major issues with our rail network and that there are also major issues with the fare structure. But I also think it comes in for a lot of un-neccesary flack from people who either don't understand or simply don't care about the challenges involved with operating such a network.
It remains my humble opinion that the Railways Act of 1993 is the biggest mistake in the history of our transport system and is responsible for much of the issues that we face today. You cannot blame a private company for attempting to maximise profit. The primary goal of a private company is to maximise shareholder value. This is why they exist. The only way to prevent companies working purely for shareholder value is to have loads of complex regulation, which we have (And my gosh is it ridiculous, did you know some of it even stifles competition to avoid reducing the attractiveness of some of the other franchises?). And IMHO when it comes to public services, public ownership, for all its inefficiencies, is better than heavily regulated private ownership.
In it's dying days, the Intercity sector of British Rail was profitable - and that includes accounting for the fact that the CrossCountry section of Intercity was loss making. Why? Because long-distance Intercity rail can be run with almost airline levels of efficiency which increase profitability, whereas the once an hour service to Middle of Nowhere Central which provides a lifeline for its residents never can. Much of the rail network is and always will be loss making - it simply costs more to run than it will ever generate in income but as a valuable public service, it should remain. And is why the government pumps billions in subsidies into the network each year...
Commuters complaints about overcrowding are an interesting one. Is it even reasonable to expect a commuter rail service into a capital city to have ample spare seating in rush hour? Can you imagine how much cost and overcapacity at offpeak times it would introduce? Everyone holds Japan up as a utopia of railway awesomeness. Have you SEEN the levels of overcrowding on a Japanese commuter train?
Commuter rail into capital cities -anywhere in the world - is very busy. It's just how it works.
The other curious issue is peoples expectation that there should be available value priced walk-on long distance fares. Why do people think this? Do they expect to be able to pitch up at Heathrow for a 4 hour flight an hour before it takes off and buy a cheap ticket? Of course not, so why is a 4 hour train journey any different? You HAVE to manage capacity and price is the best way to do this. Ever increasing prices closer to the date of travel is an excellent way of managing capacity and ensuring that 500 people don't decide to buy a ticket for a train with 300 reserved advance purchase seats and total capacity of only 600 10 minutes before travel. The majority of people, even those who don't care to admit it, will not routinely make impulse zero-notice many-hundred-mile rail journeys. The few that do must pay for that.
Devils advocate: According to the laws of supply and demand, price isn't high enough...