Google account not saving Wifi passwords, apps, etc
That's a pretty well known "feature". Don't worry, your data is backed up there – it only does not restore. And you cannot even really delete it there. So in some way, it's "safe"...

Things you might want to look up in this context:


What exactly is synced with Google?
Underlines what I've said before, and also shows you ways to check what's "synced"
Google Backup: Multiple devices using the same account - what happens on Restore?
Plenty of details on how that "Google Cloud Backup" works (and sometimes fails)
What info does Google backup?
Well, the title says it all :)
Issue 17354: "Automatic Restore" rarely works, and then only partially
What I already indicated above, and most likely the answer to your current issue. Note that this ticket was opened in June, 2011 – and still has the status "New". One of the comments also includes a possible work-around:


  Here's what I did that worked. I factory reset the device (again), and then at the very first screen (where you choose the language), I turn it off. I put in a difference sim card, turn it on and then proceed with the normal setup. This worked for my Nexus 4.

Heise on undeletable WiFi Passwords (German)
If you don't believe me about "undeletable backups", this is my reference. The article is in German, and the publisher (Heise Verlag) is one of the most famous and most trusted sources here in Germany, concerning IT topics.


There are many many more references I could give, but that would be a bit much for here. So a last hint: check the "Linked" and "Related" question links on the ASE Q&amp;As I've linked here.