And indeed, other arms of the space industry need much more funding. They will ultimately do all the common varieties of manned spaceflight better, that is inevitable.
The question is, will problems be solved by reducing NASA's budget? I think that is incredibly fucking unlikely. Instead as far as I am concerned we should be shoveling money at all of them like coal into a locomotive. Don't reduce NASAs budget so you can give more to Boeing and SpaceX.. give more to Boeing and SpaceX in spite of NASA's budget.
One half of a penny of every dollar you pay in (federal) taxes goes to science^. That is appalling. For as shitty and expensive as those shuttles were though, that money got us more return than pretty much the rest of that dollar.
If you look at how we budget for science and think "NASA is getting too much" instead of "Science is not getting enough", then you are missing the bigger picture.
^(ie, NASA. the money spent on the NSF isn't even worth bothering to include...)