Oh grow up. The slows have been closed temporarily to allow the re-doubling, upgrade and electrification to happen. By being closed they can get far more done in less time than having endless evening and weekend closures.
Major works like that don't happen by magic - it's not like relaying track on a Hornby set regardless of what you think.
Please don't tell me to grow up. I would actually agree with you if work was actually done in recent weeks. Perhaps I don't know every little thing there is to do with railways and their construction, but having being down that line on recent occasions I can report the following (lets base this on the fact that the last trains ran early April on that line if my sources are correct).
1) Signals are still in place where the 2nd line would go (the track that is laid won't be joined up until they go).
2) No new track has been laid
3) No electrification work has taken place
In fact, all has been done is a bit of ballast movement. There are some light digger equipment littered around. Considering your correct statement that the line was closed and they could work quicker with the line out of service, Its a very poor assessment of productivity done in the time we are talking here. I'd expect very heavy machinery, a permanent staff presence and a lot of noise of happening. On every occasion I've been down there I can hear birds chirping in the distance. There is literally nothing going on. I was in Japan the whole of April, in the time I left and returned some Gantries on the fast lines have been put up, which is not part of the line which was closed. Considering this thread is about getting things moving, for the better, with improvements. Things are going slower than snail pace. I'm sure NR are short on resources and things need to fall into place before the next phase can go on, that is always the excuse. However, if that was the case, why shut the railway so early? Its a bit like road work cones that are out 6 months in advance of any work done etc.