suppressed by - guess who? - Boeing and the other aircraft manufacturers
Do you have evidence for this? How would they go about suppressing Burnelli's ideas? He was flying planes before the B247 or DC-3, so it's not as if they had a stranglehold on the means of production.
Northrop ... stability problems which could not be rectified.
The B-49 did wallow in yaw, but that could have been rectified. The B-35/B-49 lost out because it was shorter ranged than the B-36, and slower than the B-47. Besides, Convair had more clout with Congress. (BTW, the B-2's yaw stability is ensured by computers.)
Yahoo: the same design could be modified for military and commercial clients and produced in a variety of sizes.
Yeah, like the 777 is a larger 767. Conventional airliners can be stretched by adding fuselage barrel sections & beefing up structure. It's hard to see how a BWB could be so easily stretched. In the early days of turbojet engines, it was said that jets are so simple, their designs could be scaled up and down with ease, but in reality, it is a big deal to upgrade an existing engine's thrust, not to mention scaling it up and down.
Boeing's official news release relating to that same event (opening the Madrid research center) http://www.boeing.com/news/releases/2002/q3/nr_020709a.html
makes no mention of the "bat jet". This may be a pet of the Phantom Works, but the commercial aircraft division doesn't seem to be promoting it.