Multiple manufacturers create competition,
"orphan" protection, and incentive to design more features.
Open ended for future technology and features.
Standardized track signal allows loco interchangeability
with various DCC manufacturers.
More stable because the power is the signal,
and vice versa.
DCC locos can run on a standard DC analog layout,
with the exception of some Wangrow decoders.
DCC layouts can run one DC analog loco along
with all the DCC locos, with the exception that SystemOne requires
modification to do this.
More accurate throttle control available -
with Digitrax FX decoders.
More optional accessories available.
Third party companies building more accessories.
The number one reason! Would
you rather have analog or DIGITAL video and audio? Well...