This is something that really irritates me as well.
Personally, I hate having to use PDF files - the constant use of these blasted things has done more to screw up my eyes (I now have to go to the opticians as a matter of priority as my close sight has been ruined by computer screens, and having to use PDF all the time really is not helping the situation).
Even setting this aside, given the cost of Nuendo, a printed manual should be included. The so-called environmental argument is BS, as trees for pulping to make paper are all grown specifically for the purpose and the net “gain” by not printing manuals is negligible if there is one at all.
I will not be buying WaveLab 8 because of the lack of printed manual - It is that simple - and if Nuendo also goes down this path then I will be reconsidering my position there as well. I like my books - proper, paper & glue books that I can take with me anywhere & sit down with - and before anybody bangs on about how a tablet will do this, let me please point out the environmental impact of making these tablets (including their batteries and the other nasties in their construction & given their very short life span) is considerably higher than printing manuals will ever be.