Do chess players really have style or weaknesses?

I was wondering if chess players really do have a style like tactical or positional or is it like Magnus carlsen said: Players with preferences are players with weaknesses.

For instance a very well known example are the Kasparov - Karpov matches where we could say that Kasparov had an attacking style and Karpov the positional style but there are many games in their world championships which would reverse this. Also Kasparov mentioned that he learned a lot of positional chess thanks to playing against Karpov. So we could say that even Kasparov had some weaknesses in positional chess and therefore he would focus on more attacking style in the beginning of the first matches?

These forums are also an excellent example whereby a lot of players like to have tactical or positional opening repertoires? Even though it's often up to the opponent how tactical or positional it will be I guess.

You make an excellent point. But the attacking and positional stuff also depends on what kind of moves you are willing to play. Players who make moves that offer big risk for reward can usually be considered aggressive like Tal, but players who prefer positional chess will not make those big sacrifices usually and will play quiter more sound moves in order not to give opponent a lot of chance to get an advantage.

Hmm yes but even Tal had a period where he just blew away his opposition and he had a score of 80-0 or something. He wouldn't have made such a score with his sacrificial chess style.

Tal's chess play I see as very positional and his intuition tells him if his opponent broke positional rules and he should sacrifice to take advantage of that?

Obviously Tal's not going to sacrifice a rook every game to try to get a win, but he certainly made more sacrifices than the average GM. And he relied a lot on his intutition which made him do some very unjustified sacrifices in the eyes of computers and  sometimes the opponents he was playing woudn't even make a positional mistake that lead to the scacrifice.

The best players try to have no style, because style is weakness. They generally fail, but that is their aim. 

Karpov famously claimed not to have any style, but there were positions that he played better than others. Every world champion has strengths and weaknesses. The goal is to eliminate those weaknesses. 

Style is not nearly as pronounced as it was 50 years ago, but it still exists. 

Style isn't openings. Nearly every opening can be either quiet or sharp. Style is more like what a player chooses... when there is a choice.

For example trading into a favorable endgame, or avoiding an exchange or two to continuing in a favorable middlegame.

For amateurs it's more like:

"I'm uncomfortable / unknowledgeable in _____ so I refuse to enter those positions."

You could call that a style, but because it's not really a choice it may not be the most accurate word.

I think "style" only can develop after a certain amount of mastery, far more than I have right now to know how much is needed.  That said, we could look at the candidates match in Moscow and see players with roughly equal results and see that differing styles lead to roughly the same results.  That could be differing weaknesses leading to the same result, but maybe at that point maybe discussing weaknesses/preferences/style becomes a discussion about aesthetics or philiosophy or free will or what it means to be human.  We all like things, does that mean we have weaknesses for them?