First of all, what I addressed was a very narrow section of communication (cussing/profanity/vulgarity) and a very specific attitude towards it (justifying/excusing). I believe and am thoroughly convinced that the Scriptures are perfectly clear on this matter and a.) it is first and foremost offensive to God because it is ungodly and b.) Christians have no business using this kind of language or excusing it away.
With that said however, I need to simply say that this does not mean that ANY of us have arrived at 100% sanctification or that we ought to look down our noses at those who do speak this way, as if to say "I am better than you". Not by a long shot, on either point. If we do, then shame on us for such pride, and we'd better watch out because God has a very effective (and often humiliating and painful) way of revealing that pride still lingering in our own hearts.
As Christians, we're all in a different place maturity wise. Even the most seasoned saints among us who have been walking with God for 50+ years will confess that they still battle the tongue and need prayer to keep their attitude in check. None of us will arrive at 100% sanctification while still in the flesh. If we all lived to be 1,000 years old, we'd still battle the temptations of the flesh because we'd still be in the flesh. In other words, we all still do things, say things, feel things and think things that we shouldn't. All of us - so there is never a moment we can sit on a superior pedestal and have an arrogant attitude about any of this. Being convicted that this is a wrong way of speech and speaking up against those who do this and excuse it away, is not to say that "they" are wicked and horrile people and we are not, but it is to say that we're all in the same boat. Some of us (for whatever reason I cannot fully explain) are just far more mindful of this and sensitive to it, than others.
The other clarification I want to make is on the kinds of speech I didn't really address. A lot of times when this subject comes up, folks will mention that it's not just cuss words that are so destructive, but all sorts of other words as well, as well as, the intention behind those words. Examples of this kind of speech that do not contain cuss words at all would be "you're so stupid" and "you'll never amount to anything" or the worst one I think I ever heard "I wish you were never born". I heard an old woman say that once to a little kid, and it was quite frankly one of the worst things I think I've ever heard anyone say. Much worse than "I hate you", which is yet another example of corrupt communication that does not contain a single cuss word. While these sentiments do not contain cuss words, they are just as damaging (some would say moreso) to a child's ears as if you were able to literally chip away at their spirit with a sharp knife.
I didn't address that kind of speech simply because it generally isn't that kind of speech that any Christian would be caught defending or making excuses for, or calling you a Puritanical, prudish legalist if you don't agree with them on it. However, to be perfectly honest, it is often that kind of speech as well, that does contain vulgar or obscene words peppered into the phrases. "You're so _____ stupid" and "you're a piece of ______" are two phrases I used to hear a young mom say to her kids on a fairly regular basis when I was unsaved. I didn't spend much time around her personally because quite frankly she wasn't a very nice person to anyone (young or old), but she did run in the same circles I did, so I did hear her speak quite often. Her kids got the added bonus of growing up hearing both kinds of speech blended into the same sentiment. Her kids grew up knowing full well that cuss words carry the same weight as hateful words used intentionally to tear someone down.
For A LOT of people who grew up hearing words like that, they did in fact come in the same phrasing as the destructive words of condemnation, so they are to this day, still associated with that kind of verbal abuse.
Once again, I wish to say that speaking this way is wrong, period. It doesn't mean that those who don't are "better than" anyone else, it simply means their hearts are convicted by it, and they're aiming for a higher standard. It also doesn't mean that those who don't, don't still have ungodly thoughts or say ungodly things - because most of us still do. It does mean however that rather than just accept it as the way it is, we take the battle against our own flesh as serious as it is, and strive daily to overcome these temptations to express ourselves in this way.
It's not easy and we often fail (even daily), but its absolutely worth it.