Why is the PM fueling this Senate scandal?

The Conservative government under Stephen Harper has been closely controlled and has rarely acted with a clear goal or agenda.  It is this almost micro managing of Canadian politics by Stephen Harper that makes me wonder what is going with the Senate scandal.

The whole affair seems to be a small minded internecine war within the Conservatives but that is out of character for the party.   It should have been clear that going after Duffy, Wallin and Brazeau with this motion would make nationwide headline news and make the PMO look bad out of it all.   This is a story without a good message for the right to take to their base.   Remember, these are three senators appointed by Harper.  There are 11 members of the current Conservative caucus that were no appointed by Harper so why go after these three?   I can not believe that political stupidity or revenge are the cause of all this.

Either the government has become arrogant beyond rationality, which might be the case but I do not think so, or the government has some other shoe to drop in this whole Senate scandal.  For there to be another shoe to drop, there has to be some benefit to the PM.  How could the government use this Senate scandal to further its political goals?  

Just thinking out loud here,

• Create the context to abolish the Senate - I am not convinced of this because it is not playing out in such a way to make the Senate look bad enough to get enough provinces on board with abolition.   The reality is that the vast majority of Canadians already think the Senate are over paid entitled ex political hacks, this scandal is unlikely to have made people think worse of the Senate. 
• Use the Senate scandal against the opposition - This does not work with the NDP since the NDP is opposed to the Senate but could it work against the Liberals?    Have the Liberals said too much in favour of the Senate?   Is their a Trudeau quote on the Senate that can be used?   Are there similar or worse financial issues with Liberal Senators that could come out closer to an election?
• Scare Conservative MPs into toeing the line - Maybe by sacrificing a few very expendable Senators the government is hoping to scare the MPs and show them what will happen to them if they cross the PMO?

That sort of exhausts the things I can think of why this scandal is happening.   I feel like there is something coming.