Another Justification
(in case the first one wasn't good enough)
Low surface brightness galaxies have the same properties as the higher surface brightness galaxies:
Stars ranging from very young through very old
Sizes ranging from big & bright to small and faint
The same large scale distribution of galaxies
But, LSB Galaxies are NOT
Faded high surface brightness galaxies
HSB galaxies that have been "stretched out"
A whole different class of galaxies
Because they're
diffuse
LSB galaxies allow for more detailed studies of their stars
LSB galaxies can help explain how all types of stars
and galaxies form and evolve