hmm... is it? VII - I is what? is that minor or major?
Parallels are used sometimes in cadences and in arpeggio chains.
Remember, the whole idea of parallels is to prevent the collapse of two voices into one. "Doublings"(which might be mistaken for parallels) are very popular and occur all the time.
Only thing I can think of you you are refering to is uneven parallel 5ths. i.e., the dim5th interval moving to a P5 or vice versa(although one way is better than the other supposedly). The reason is simply because they are not Parallel P5ths.