score:8
As for "how other Christians view this", the answer is "it depends on the Christian in question."
Some Christians, as you pointed out, believe these are signs of the devil, others don't. Just like some Christians see Harry Potter as Satan's way of luring kids into witchcraft, while others think it's a good read and good movies. Some Christians see Satanic symbols in the Proctor and Gamble logo, or the mark of the beast in UPC barcodes.
As for whether or not it matters, I defer to Romans 14 (KJV)
1 Him that is weak in the faith receive ye, but not to doubtful disputations.
2 For one believeth that he may eat all things: another, who is weak, eateth herbs.
3 Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth: for God hath received him.
4 Who art thou that judgest another man's servant? to his own master he standeth or falleth. Yea, he shall be holden up: for God is able to make him stand.
5 One man esteemeth one day above another: another esteemeth every day alike. Let every man be fully persuaded in his own mind.
....
14 I know, and am persuaded by the Lord Jesus, that there is nothing unclean of itself: but to him that esteemeth any thing to be unclean, to him it is unclean.
To those that believe these are Satan's signs, it matters. To those that don't, it doesn't.
Upvote:3
The "I love you" sign, or Horns, as they're known in the Heavy Metal scene of wherever Heavy Metal is played are attributed to the late Ronnie James Dio of the group Dio (and for a time Black Sabbath).
He got the sign... From his grandmother.
However, it is not wise to trivialize the occult, just saying something has no meaning or no power ignores spiritual realities, as well as powerful psychological forces.
For instance, at a Metallica concert, first you put your fist in the air, then you do the horns and you're going along with the beat so it's almost as of you're worshipping the band by simulating the same postures used for worship by humans throughout history. And now they're playing Creeping Death and you're chanting "Die die die" with 40,000 other droogs and next thing you know someone's heart is literally being pulled still beating out of their chest while their body is being lowered into a pit of lava.
Ok, that last part was from the Temple of Doom, but the rest is the truth and the only cure, as Frank Zappa said, is to "stick closer to Church-oriented activities".