I'll try to explain this, but probably won't do a very good job of it, and then withdraw.
In a society where religion is at the very core of daily life, god becomes, for the believers, a very real entity. In such a society, losing your temper with someone and saying, for example, "Damn you !" is calling on god to condemn someone to eternal punishment for no good reason. This puts your soul at risk, and also the souls of those who support you. In a society with that mindset, blasphemy laws make sense to THEM.
Islam itself is not a //despicable philosophy// but it's adherents are human and just as prey to all the nasty little thoughts, jealousies and ambitions that affect everyone else in the world. I'm sure you can think of a few people in this country who have their own "despicable philosophy".
Until you have complete separation of church and state within a nation, the church will always have a great deal of influence over the laws of of that nation, and even with separation enshrined in law the church can still exert a lot of influence over government (think of the Republic of Ireland, or even the USA). I don't think that separation is going to happen any time soon in places like Pakistan, but I do believe that it will happen eventually