I like studying old typefaces. But why bother? Below are some possible reasons:

It's What Historians Are Supposed Do
Is writing about type history a career-enhancing activity? For myself, I would answer "possibly." Once you become known for something, and get asked to do more of it, saying no seems lazy or overly cautious. Why not? However, in my case, since I am not a full-time academic, the possible advantages to my career are slight. There is still some cultural prestige attached to publishing, but I'm not building up qualifications for tenure.

Curiosity
By curiosity I mean questioning and analyzing everything, a kind of untethered, nerdy enthusiasm about life. Yes, this is a part of the desire to investigate old type. I have discovered certain questions, and enjoy finding answers. If I had studied the history of indoor plumbing instead of type, my curiosity may have found a different focus.

Do It To Make The World Better
The common reason given for the study and teaching of design history is that it enriches the field of design. This justification suggests that designers can do a better job when they know their history, and also, in the context of education, assumes that the study of history fortifies design as a profession worthy of higher education. I suspect, however, that knowledge of history often has little to do with the practice of design. Mysterious things called trends and fashion determine whether or not designers use antique typefaces "well" or not. When the topics of design history study align with a design trends, history can appear influential. But many historians work on topics that are obscure, and maintain, rather than inspire, interest in their subjects. It is also futile for historians to think that their research will discipline designers into using type in historically "correct" ways.
     Designers will do what they want, as long as novelty and experimentation are valued in design.
For most designers, history is visual. They see something old and fall in love because they project longing onto objects, and think life the in the eighteenth or nineteenth centuries might have been better somehow. Antique design can evoke something they want to identify with. They — or, I should say, we — forget about bad dentistry and imagine past lives full of more meaningful work, warmer communities, or adventure. Sometimes history assumes value by popping these dreamy bubbles, but haunting "what ifs" remain. What if life really was better in ways that deserve revival?
     History — including type history — is important partly because it reminds us of options that have been forgotten. Most people will assume the options were better than present ones. For instance, if you were in a design school in the 1980s, the questioning of modernism and rediscovery of nineteenth-century type was exciting because the openness to ornament seemed more receptive to beauty and less scientific. But history can also remind us of things that weren't better. The contrast between typographic openness now and reactionary polemics at any time remind us of our current imperfect tolerance for design diversity (in many parts of the world). History reminds us of past limitations, dogmas, and fights, of the effort that has formed the present, by generations distant enough to be beyond the reach of oral history.
     The value of history is not simply summarized in the adage about the ignorant being condemned to repeat past mistakes. Living with an awareness of history is like living with an archive of past formulas and strategies for living, and constantly juggling them and evaluating them in response to new problems. There are such things as new problems in the world, and the more data we have to draw on, the better — though a lack of history does not eliminate the possibility of brilliant, fresh solutions.
     I am suspicious of design that deliberately spurns history. Take Futurism. It was impatient, testosterone-driven, self-destructive, and doomed. Futurism is the James Dean of design, killed young in a speeding car. As a wake-up for a complacent Europe, it had value, and perhaps cultures need impetuous, ahistorical youth to occasionally slap them around, despite the danger. Historians can penetrate the glamour of design, reveal the specificity of its context, and help avoid vacuous or dangerous imitation.
     History buttresses the importance of design because it assumes that design is part of a larger context, that design matters. In rich societies, in which design is ubiquitous and might be taken for granted, history reminds us, like a good disaster movie, that our current reality could be otherwise. This warning, then, reminds us of our ongoing responsibilities. We may be bored by our work, unwilling to design another sign or website or book, but what are the repercussions of not doing so?