I believe these things can take away your piety. I believe that all forms of entertainment are from shaytaan. Just look at the 'realit shows' these things hook millions of people in front of their tv screens. When you step back and look at it you know that the contents just rubbish but people seem to want more.
We caould all do better thing instead like reading the Holy Qur'an or listening to recitations etc.
I agree with you, I think for some people it does affect their piety a lot, especially when it interferes with obligatory practices, like delaying prayer because you're in the middle of a movie, or listening to music while the adhan is on and not hearing it, or trying to fit into some kind of worldly status or trying to win a popularity contest by indulging in these things so that you'd have more in common with the people etc. And we can always find better things to do to increase our rewards in dunyaa than watching a movie or listening to a song, but the reality is, not a lot of us spend time worshipping Allah 24/7, and for some, watching a movie is a lot less evil than doing other things. You could also include social networks in this discussion, or a lot of other time-wasting activities, but at the end of the day, we're all human and we don't like being serious all the time.
I personally believe if a somewhat halal secular activity is done sparingly and with a sound mind, it shouldn't be a problem. If it's something that becomes a habit, addiction, or over-indulgence, then that's where the person needs to step back and re-evaluate the way he spends his time.
I think it's great mashallah that you are able to quit music and watching tv. May allah continue to guide and you increase your worship and deeds ameen. I can't say anything against quitting these things because as you said, there are better things to do with our time, but at the same time for me personally, I can't say it would make too much of a difference in my life if I quit watching movies..I don't think I'd spend my time more wisely if I actively removed it, get what I mean? I'd probably just go online and waste the same amount of time doing something else, and this is in my own personal weakness/flaw. Some days I just want to laugh and unwind and I can find that in a show or movie.
fi aman Allah
w'salaam