I'm standing in Peter Drucker's long shadow here, so everything I say will be derivative and incomplete. But hey, half formed is better than no-formed, yes? Like a cake that is missing sugar and eggs, or a car without a gas tank, or any other bad analogy I could come up with if I was being paid by the hour to write this blog.
Once a firm is established by a group of people it is invested with a sense of reality that can be remarkably effective at fooling everybody--including legal systems. Since we live in an age of easily retrievable data, the symbol of a firm can persist indefinitely. The Atari trademark is still a real thing. I would not doubt that some lawyer is working hard on some idiotic brief about the matter. Someday, some other lawyer will be doing the same things for the Apple logo: "From now on all fruit, unbitten or not, shall belong to Base R...all hail Jobs, all hail Jobs"
The slow, hidden death of a firm can occasionally inoculate people against reality. But this is a good thing, because if a person invested in the idea of the firm maintains that sense of commitment, then the firm can persist. One good client can come along and change the course of things. One bad check, on the other hand, doesn't spell doom. The firm exists as long as at least one person shows up.