Fatboy. It sounds to me that what you are seeing a lot of, are "dummy bases" or "dev bases".
These are inactive bases added to ease the CNFOs (Could Not Find Oppent). They will have empty Squad Centres, no GR active (Guard Reserve), a low rank, and all resources will be in the collectors.
The reason they have little resources to offer is because they are never collected by a player and are being hit over and over so do not have much chance to accumulate said resources.
On the plus side, these bases are a good source of 100% offensive wins and medal gain, with no nasty surprises to deal with.
On the down side, as you say, you're not going to get rich from them.
I hope that has answered part of your question in some way.
Playing since day one.
Han's_ScoundrelsWe usually have a spot open for active Rebel players. Request/donate often. Quick fills. Have fun.
Maxed-out Squad Perks.