Why do some Muslims mix Islam with politics when Islam is a personal matter?

I was once told, " Islam is not a system as modern muslim ideologists want it to have. Islam is also not a subject - Islam is a stance towards God I.e. the manner of surrendering."  I agreed that Islam was a stance or orientation towards god and cannot be reduced to some mechanistic system. That was common ground.  However, without qualification, such a claim relies on ideological assumptions, usually concealed, bringing everyone who makes such claims into the fold of ideology.  What did I mean by that?  Well, if Islam is not assumed to be social, collective or political, it will be a personal stance, between the individual and god. This is arguably relies on a secular individualist interpretation, reducing Islam to a religion. "Religion" is a modern construct, as historically civilisations saw matters of the divine interwoven with their systems of life, institutions, practices, traditions and so on. There was never a neat delineation between a personal faith and social matters that the notion of religion implies.  The brother then modified his stance saying, "of course it has a social and collective frame and normative - but not in the core as some ideologists think - state, identity, the watan at all. At the core its a nexus for salvation."  Whilst I fully agree salvation is never at essence about the modern nation state - however this unqualified claim of it is simply salvation again faces the same problem as the previous claim. Namely, without qualification it relies upon unexplored ideological assumptions - making all who interpret into ideologues of one persuasion or another.  If Islam is not assumed to be social, collective or political, salvation must be assumed to be a personal affair, between the individual and God.  How then to explain the voluminous evidences that oppose this rendition?  The primordial gathering of the souls was never a personal meeting with God;  Birth is into a social and political collective (ie family/tribe/kindship ties...); Even death is not alone, with salat al-janaza (the funeral prayer) read by the community over the corpse; The time in the grave entails accompaniment with good deeds in the form of a youth; Resurrection is with the a'imma (the leaders one followed), and  The final accountability making one drag in everyone one encountered in life as the finger of blame is pointed to offload contributory sin.  There is a personal dimension to our journey in life, and a collective one. To save "myself", I must save "ourselves".

Today the world's Muslim population exceeds over 1.8 billion. That's a huge number. A Muslim, may he be a staunch follower of Islam or not, he doesn't compromise over the integrity of the principles laid down by Islam. This means that as opposed to other disciplines, Muslims are pressed under religious pressure to follow a rule or a party, who is allegedly using Islam as a tool to gain political power. This has many instances. Zia ul Haq, Pakistan's military dictator, did something similar. After restoring his rule, he held a national referendum, where he asked whether the people would like the Islamic government to continue further or not. By Islamic, he meant himself as if he had been adopting many policies that were Islam related. The Pakistanis eventually voted to continue the Islamic government, putting Zia under further rule.