BSA could have designed a modern 4 cylinder engine but I doubt that BSA could have built it. You need precision and quality control to build something like the CB750 not something that Small Heath was known for.
You forget that BSA was much more than a manufacturer of motorcycles. BSA was one of Britain's major engineering groups and made a vast amount of the tooling for the wider engineering and precision engineering industry. BSA Tools had continued as a respected business until recently.
BSA was also a major supplier of components and castings to many other businesses.
Management shortcomings and failings are widely and correctly referred to, but most commentators forget the economic turbulence and expecially the politics associated with government policies. (I'll steer clear of politics and government policies as there is still no proper, comprehensive study of all the relevant factors many of us lived through and remember).
However, the involvement of Dennis Poore, ex 1950s racing driver and his political affiliations and contacts cannot be ignored.
He had become Chairman of Manganese Bronze Holdings, which made ships propellers and in 1960s bought Villiers. He then sold the propeller business and used the cash to start buying up motorcycle companies, starting with AMC, using Villiers, which had become a finance/investment company to do it. It could be argued that there was genuine poitical interest in Government to save the bike industry, but Poore was one of the early (but not the first) Financial Engineers, who focused on the money, rather than the engineering and certainly not the people. He sold off the non-bike parts of BSA & shut down the guns business very quickly and triggered union troubles (let's all blame the unions, or maybe not?) by sacking 67% of the workforce in one go.
The new owners of BSA (I stress, again, they did not just "buy the name") have gone on record as saying that BSAOC has been responsible for keeping the brand name, the brand values and the spirit of BSA alive, after the collapse of the company itself. Phil and Chris and I have met the people behind Classic Legends (parent company of BSA) and can confirm they are far more interested in BSA and Bikes than they are in money. Phil & I contributed to the initial design specification meeting for the new bike and it was us who came up with "The Bike BSA Would be Building if Production Had Continued".
We also met the Engine Designer - the range and extent of his work in racing and other branches of engine design make some of the media commentaries on the new BSA engine nothing short of ludicrous. Hey-ho, maybe the "Experts" should actually ask the man himself?
We also met Bal the actual Designer of the new BSA. A key element of the design was to build a platform which owners could adapt to suit themselves. Just like we used to do before the 1980s, when "originality" became the thing. Again, the media experts announced that the Scrambler shown at the NEC in December was a "soon to be announced new version".
Pardon my laughing, but the fact is that Bal and 2 of his colleagues built that bike in their spare time in 3 weeks using off-the-shelf components as a bit of fun and to show how adaptable his design is! Bal also supplied the Scrambler photo that appeared on the front of The Star.
BSA is alive and well, never really went away and has been kept in the eyes of decision makers by us all, the proud and friendly and happy Members of The BSA Owners' Club.