Isn't that what you call discipleship?
Unfortunately, this is what many Baptist Churches call Discipleship, when nothing could be further from the truth.
Discipleship has very little to do with telling someone what dress is proper, or what music they should be embracing, or how they shouldn't be goin to the show on Saturday night.
When you disciple someone, you teach them how to study the Bible, and you walk them through the basics of doctrine, and you go though the Biblical philosophy of your church and help them get prepared to learn deeper truth on their own, you don't give them a list of do's and don'ts, or even shoulds and shouldn'ts. When you disciple someone properly these issues will come up, for sure, and you get great chances to guide them to make better decisions, but not by you ramming something down their throat, but by them going to the scriptures and actually learning new truth from that source, not just the spoonfeeding of a more "mature" christian.
The main problem is, people who don't bother to teach new believers (and this applies to children too!) how to study and apply scripture for themselves, and so you end up with people who are fine, as long as they are within the boundaries you have created for them, but when they come into a new situation, many times have no idea how to even evaluate it, or their response in a Biblical way, because they only know, "well, I'm not supposed to do ..." Many well meaning people are more that happy to impart their own standards on others, but either choose not to, or are not mature enough themselves to teach someone how to develop Biblical standards for themselves, and how to apply Biblical principles in decision making. Thats fine if you want that person to still be coming to you and asking for the bottle when they should be eating steak, but it is a poor way to develop true disciples of Christ, and when their "role model" fails or stumbles, many of them fall away or become bitter, because their dependence is on other christians, not on God and the Bible.