Bullshit, both dedicated servers and vps can be managed or unmanaged with root access..
Anyway we just have to wait for answers the owners sent to some ISP's to get a server, with good protection, asap 
I am not arguing but to gain some info and fix some.., VPS is virtual server so the hoster provider setup for you a part of the Ram and part of the processor for you to use, but the dedicated server you have the whole processor and whole thing...
VPS = Part of the machine
Dedicated = The machine it self..
True there are 2 types , unmanaged and managed ... unmanaged you must fix your own problems and thats 75% of all servers because managed is expensive, but the VPS, you doesn't have root access? You can host VPS on dedicated servers and thats what resellers do.
When you get VPS it would be like you got part of machine, if you had root access you would spoil other VPS which are hosted in same...
Well that's what I know.. sorry if I am wrong or mis-wrote ... :/