Tierney plays against the best players in the world when he plays for Celtic in the Champions League mate. I can understand why any player would want to leave Scottish football to play in the Premier League, but Tierney is a real Celtic supporter, not a badge kisser, and the main reason he would go to Everton would be money, and the possibility of eventually moving on to Man Utd, Man City, Spurs, or even your close neighbour. From the info l've heard, he has already turned down a move to an EPL club.
If Virgil van Dijk had signed for Everton from Celtic, the Everton fans would have been making the same points then, as they're making about Tierney on this thread. The fact is, Tierney is a cracking young player, and Everton will be doing well to get him. I know for a fact that Spurs were looking at Tierney, and Ajer.
Some of the opinions on this thread are, to say the least, ill informed, and in some cases, like the one that Celtic wouldn't sign a Muslim player, absolutely bizarre. The arrogance of some of the Everton fans here is absolutely breath taking, especially considering the lack of success the club has had over the last 20 years. Tommy Graveson didn't exactly set the heather on fire when he was up against these "farmers" you speak of.
If Tierney does sign for Everton, and in my opinion it looks like Celtic want to sell one of our top players, you should be really happy about it, as you'll be getting an absolutely fantastic young player, who can only improve.