Maybe, it's just a stylistic thing. I you consider the "strong" beats in the measure to represent quarter notes, then some weird denominators arise when those strong notes are irregularly spaced.
If this is your strong beat pattern:
|.|.|.|.|.
Then you would do 5/4
But if this were your beat pattern:
|..|.
Then, if those strong beats serve a musically similar purpose to regular quarter notes, then those subdivisions (3 and 2) represent eight notes. Since the "quarter note beats" aren't regular, you have to measure in 8th notes, giving a 5/8 signature.