I'm sorry, but if I'm really going to be honest then you have an incredibly simplistic and narrow view of what the stadium should be. You want the club to spend £2b+ on what would basically be a bowl with seats and grass inside it, that only gets any footfall once or maybe twice a week, and not at all for 3 months of the year? You think that is a good use of that kind of money?
Firstly, they're building this to underpin the regeneration of the entire area. It needs to be for the govt to get involved in helping improve transport links, as a bare minimum. Because of that it needs to be much more of a hub for people, not just a stadium for match days. It's fine if that's all you use it for, but it's not being built just for you.
Secondly, this is going to be a 100,000 seater stadium. How many clubs have actually built that from scratch? It's fine for Everton to build a stadium just for football, because it's half the size, and they're Everton so nobody gives a shit outside of Liverpool. People aren't going to travel a thousand miles to see it. United are trying to build a monument, not just a stadium. A monument to United, to football, and to Manchester.
Again, it's fine if you don't like the designs. I'm not entirely sold on the spikes either (although I'd urge people to go and look at all the pictures and the video with Foster, and not just the select few media outlets are running with), but I find it disappointing that so many people just want to build OT, but bigger.