I think the main reason is simply that most people get much more satisfaction from blaming individual 'villains' rather than faceless corporate bodies.
The Board of Trade thinking on the matter was, I suspect, a good deal more complicated than most accounts suggest. I have been doing some background reading of old parliamentary questions and debates relating to the BoT regulations and I get the impression that they had been deliberately allowing the lifeboat requirements to lapse in order to gain more support for improved compartmentalisation. Their political calculation was that they wouldn't get simultaneous parliamentary support for both and I suspect, given the domination of the House of Commons by business interest in that era, that they were probably correct.