I would not call the promotion of bills to mandate the use of Open Source or Free Software in government to be a "politicizing" of the issue. Politicizing implies there's some fuzzy basis and room for debate. Frankly I don't see where the debate lies. The government has a higher responsibility than a corporation or private citizen with regard to the way it obtains, stores, and makes data available to the public. After all it is our information, we own it, and the government is only a central database, so to speak. Open Source - Free Software specifically - is the only approach that is demonstrably compatible with these goals and responsibilities.
Rather than reiterate the arguments put forth by Peruvian congressman, Dr. Edgar David Villanueva Nuņez let me simply refer you once more to his reply to the Microsoft executive. In his reply he invites Microsoft to put forth arguments extolling the advantages of closed-source and proprietary standards. Why not take on Villanueva's reply point-by-point or provide the arguments Microsoft has so far left unspoken?
All you have provided so far is hyperbole (the baseless "slippery slope" argument used by lazy thinkers) which does not effectively make your point. You need to provide precedents and concrete counterpoints, otherwise you're just blowing air.