Buona sera. Does it bother you when someone points out problems but does not offer any solutions? Then prepare to be annoyed because I have no great answers. If, however, you want to compare notes and possibly say, "Yeah! I see that, too!", then you're in the right place.
I also have problems with some of the "Charismatic" groups. "Speaking in tongues" can be a scary thing to experience. It certainly creeped me out the first time I was around it. Today, I believe that they are in error. Further, the Pentecostals and Charismatics are the ones most likely to say, "God said to me...", and the rest will simply accept it without checking with their Bibles. Experience and emotion are too often the sources for their "doctrines". Frinstance, Joel Osteen and Benny Hinn are not representatives of my view of Biblical Christianity!
False Christians. People make the mistake of thinking that, since the United States is "a Christian nation", if they are not actively part of another non-Christian religion, they must be Christians. Also, the word is taken to be "moral" or "nice guy". So, they claim to be Christians, but they really have no idea what that word really means. They are in for a rude surprise when they meet Jesus face to face.
Religious people. People who have gone to church, often their whole lives, and think that going to church, practicing rituals and sacraments &c. makes them Christians. Also, things done by religions in the name of Christ are just that: Religions in the name of Christ. But they are not accurate reflections of the teachings of the Bible. Look to the source, not just the followers. "Religious" people are also in for a rude surprise when they meet Jesus face to face.
Over-enthusiastic Christians. They are full of the joy of salvation, they feel good, their burden of sin is lifted. So, although they are not "grounded in the Word" and good Bible teachings, they become cheerleaders for Jesus. Sometimes they'll say things that they cannot back up. They know the Bible is true, but they do not want to admit that they cannot answer the difficulty that you just posed. But that is no reason to reject everything that they have to say.
Spiritual people. For lack of a better term. They get all religious on you, get emotional, send you those awful (and usually pseudo-Catholic) e-mails. All I can say is that they have good intentions, but some of them get on my nerves, too.
Christians judging other Christians. I have written about this elsewhere, that some people grow in the faith in different ways and speeds than others. So, some who have learned about a subject get proud and look down on those who have not shared their epiphany, or have their level of knowledge. They are often guilty of pride, and need to repent of their superior attitudes. And unbelievers, you can sit back and watch. Why not?
Superstitious religious. Can't stand it. "God will get you for that", or whatever. Turning Christ into an unbelievable superstition. The Bible doesn't teach that, neither should they.
The truth. Yep, the truth of the gospel is offensive by itself (Rom. 9.33 NASB). Who wants to hear that he has sinned (Rom 3.23)? Or that you are judged and under the death penalty, but Jesus paid your debt on the cross (Rom. 6.23)? Who wants to hear that they need to turn from their sins (2 Peter 3.9) and accept the risen (1 Cor. 15.3) Jesus as their Lord (John 1.12)? Who wants to hear that they are the property of Satan (John 8.43-45), who blinds their eyes to the saving truth (2 Cor. 4.4)? That hurts the pride. And pride will drag you into Hell, quite frankly. No, the truth is offensive enough without people being people, having emotions, viewpoints, upbringing, traditions, personalities and getting in the way of the gospel.
So, to some extent, no wonder people scoff. But humanity is diverse. Just like those who share some of your viewpoints, capice?