Lets talk in terms of forms design and comb fields. I'm having a difficult time understanding why a comb field should be used on printed form ( not talking livecycle e-form) for any purpose other than supporting intelligent character recognition (ICR) or hand-text. Why would a forms developer attempt to generate machine type into a comb field? My understanding of comb fields are that the form will be scanned and data will attempt to be extracted via a scanning solution. I think Adobe has created in its livecycle design a capability that most do not understand. Comb fields are preferred for input, however do little on the output side and are actually a hinderance in data display.
There are a lot of organizations that require combs for compliance reasons. For example there are quite a few government organizations that require that the electronic form exactly match a pre-existing paper based form (the so-called light test). If the old paper-based form has a comb, then so must the electronic version.
Also forms may be used for both print-and-fill as well as electronic entry (with the same form)
If you don't like the combs, just don't use 'em.