That's absolutely right. Few high end systems include "room correction DSP" because they are likely to be feeding similarly high end speakers. The better the system (provided it's set up properly in a sympathetically furnished room), the less the need for DSP.
Also as you say, it's a boon to DIY speaker builders who don't have the R&D and testing facilities for multiple prototypes to get an ideal response from their home-builds. Here DSP will be of enormous help. It also helps with poor / mediocre branded speakers where corners are cut, although it still won't match a well constructed and designed branded one of much the same size.
The other place where DSP may be helpful is with Home Theatre multi-speaker systems where the owner is unlikely to have the skills to set up his system for best performance. It's not easy, so resorting to DSP is almost forgivable, particularly because in HT system the audio is only part of the performance and our brains are less critical of less-than-perfect sound if they are also processing the video sensation.
However, DSP can be beneficial without spoiling the delicate signal if it's used in an active system where only the bass frequencies are sent to a dedicated bass-only amplifier that serves the bass drivers. My own speakers have this DSP facility though the software is not intuitive so I am not even using this - let alone Dirac Live.
In your later post referring to analogue, surely no one who is a true analogue fan would ever use DSP in their system as it involves analogue to digital conversion, then DSP, then digital to analogue conversion? Better perhaps to ditch the analogue source and start off with digital and thus cut out the ADC. The more a signal is processed, the more it will suffer damage.
Others (users of DSP) will disagree of course!
