Despite myself I feel exactly the same way. In the great cosmic scheme of things its not supposed to matter, as you say. But as Lesleysherwood says, no one wants to go backward.... This happens to me all of the time.
As you may know, just precisely what the scoring criteria is that HubPages uses, is a complete unfathomable mystery, and meant to be that way. They have their own "black box," as it were. Perhaps theyr afraid that if they (HubPages) stated their criteria clearly (I mean in the key to keeping a certain score, going up without going down) they would get too much "pandering" sort of work, you know (and there's plenty of that already as it is).
If I really wanted to be "anal" about this, I might note that there are some favored hubbers who are always touching the magical 100 mark, and though their score does fall its never lower than 95! And so on and so forth.