Secular principles do not necessarily contradict to Islamic principles with exception of few things. Secularism is a complex term having many different interpretations. If secularism mean equality, justice for all, freedom of religion etc then these are Islamic values as well but secular countries are not secular in true sense otherwise why public holidays only on Xmas, Easter and England often labelled as Christian country
Mostly Muslim oppose secularism because Islam is deen i.e something which is not limited to your personal life and they believe Islamic values should reflect at state level and Islamic laws should be applicable to Muslims. You think that state should have no say when dealing with matters like prostitution , drugs, alcohol, modesty etc
You've touched upon an important point, that no system is 'perfect' or static. You see this in the West currently, where right-wing parties are seeing a resurgence and pushing 'values' that smack of racism, intolerance and bigotry, values that have no place in a 'perfect secular State'. You see this in the US, where the phrase 'One nation under God' was added relatively recently. This push and pull will continue, and change (in either direction) will occur gradually.
We are unlikely to see Pakistan transform into a 'secular State' in our lifetime, but what most of us should be able to agree on is the implementation of values that both Islam & secularism agree on - like equality for everyone regardless of race, gender or faith, like the freedom to practice our faith (or lack of faith) as we see fit. As IP pointed out above, there are many, many practicing Muslims in the West who are surrounded by what some would consider 'morally sinful activities', yet these Muslims do not stray from their faith and do not berate those who do not follow their faith. The live side by side in harmony for the most part (at least in the US). Why can Pakistan not accomplish the same?
We can be nation of Muslims that also allows everyone to practice their beliefs as they see fit, especially when it comes to what people do in the privacy of their own homes. This isn't an argument to allow men to wear speedos and women to wear bikinis while walking on the street, it's an argument that we should at least stay out of people's private lives. If two consenting adults want to drink alcohol (and not drive drunk or disturb the public) in the privacy of their home, or have a physical relationship outside of marriage what does it matter to the rest of us?
Some of you may disagree with everything I wrote, and that is fine, I don't expect to change minds in an instant, but while disagreeing with me, please also respect my (and others) right to voice an opinion about the direction of the country that is different from yours, and I shall extend the same courtesy to you. At the end of the day all we can do is try and advocate in favor of our views and hope that we can eventually convince enough people to bring about change that we want to see. We might fail, and if we do so be it, but let us fail after we have had a free and equal opportunity to make our case.