You do need a good QB, but they are sacrificing 4 potentially high impact players for the possibility (which is slim) of getting 1 great QB-and giving away his #1 target.
I get the desire to take the risk, but history has proven time and again that keeping the draft capital and drafting the best available QB at the 9 spot is the higher likelihood for success. If a guy you like isn’t there, you trade down and accumulate to build upon other areas of your team.
Sacrificing the rest of your team for any position (even the most important) rarely has worked out for numerous reasons.