Google doesn't give a damn if Samsung can come in and use the same IP and have similar features on their phones. Remember, Google just wants to improve the Android experience as a whole. If they use the HTC IP in a cool way, it's good for Google if Samsung does the same thing.
I do not understand how so many still don't get why I brought up this exclusive vs non-exclusive deal. The best deal one can get is exclusive rights. The unknown here is we don't know whether Google's agreement includes (NDA) any exclusive IP.
The Motorola acquisition was both desire to exercise the IP and as a mean to defend patent wars. But people thought they were all about making new phones (which can always make more money and more ad money). In the end engineers got transferred to other teams within Google.
Of course they want to move into consumer hardware for the exact reason you listed: sell more ads. They got certain group of engineers so they can work on projects Google either haven't revealed or improving existing hardware projects, most of the code will remain proprietary. You don't see most of the Google Home code in open source Android codebase, except whatever Google believes are valuable for the community.
There is no altruism here. Otherwise there would not be any patents and any licenses except "no license" license. I suggest those downvoted me please think about why software companies want to move into consumer products in the end. Why is FB building hardware? Why Kindle in the first place? Why Google Home or Amazon Echo? Read up various highly regarded analysts' reviews on new sites. Those people do better analysis than I do here.
You wrote that Google does not have the "whole IP". You are saying that there is something that Google doesn't have access to?
If Google has non-exclusive rights to all of HTC's IP, then they do have the whole IP. They just aren't the only company with the whole IP.