EDIT to add: Before Hyperloop, it was Maglev.
And frankly, a significantly better argument against HS2 is that it's an impossibly expensive boondoggle.
Nah, it connects most of England's largest cities, and will be 2/3rds of the network which will connect all of the cities of the North of England into something approaching a single labour market. Liverpool, Leeds, Sheffield, Manchester, Birmingham will be all be within 30-50 minutes of each other, with London within an hour and a half, with trains running between destinations 2 or 3 times an hour. The value of that is enormous.
That should mean strengthening a region around Birmingham, faster links connecting the Leeds - Sheffield - Manchester triangle + tack on Liverpool, and a wide orbital around London improving connections between the towns around London that now are reduced to feeder/sleeper towns. There are towns around London that has decent direct rail tracks, but where the fastest rail route is a 2x-3x longer journey in to a London terminal and back out again. Actually run direct trains, and you suddenly have new viable commuter regions that bypass the centre.
Only after that should we think about making the links between these centres faster.
The problem of course is that many of these will need to be run at substantial losses for years before enough companies etc. will move/get established to change transport patterns, and it's so much easier to justify building more expensive routes where there is existing overcrowding.
Never mind that doing so just attracts more people.
And yes, I realise the XC trains around Birmingham (inc. to Newcastle) are frequently overcrowded, but there's a comparatively cheap solution to this: buy more trains.
https://www.railengineer.uk/2014/01/03/the-capacity-benefits...
http://www.citymetric.com/transport/hs2-isnt-about-north-eng...
The idea that it will turn a load of separate cities into one big city is basically fantasy, as i understand it - this is about HS3, but the analysis is much the same:
http://www.citymetric.com/transport/crossrail-north-really-b...
And yes, i do get all my information from CityMetric, since you ask. It's basically Buzzfeed for transport policy, i love it.