Is the Sicilian meant for chess experts only?

@LouStule, it all depends on the level of your competition. You can look up the average rating of your opposition yourself.
Yes. (For the umpteenth time!) I know a lot of National Masters (I live in New Jersey which has quite a few living here) and this seems to be their consensus of opinion.
I don't play the Sicilian but some of my opponents here play it against me when i play 1.e4 . The games more often than not ends in a "blood bath" either i get routed or they get routed. Me thinks its for the "excitement- hungry- blood thirsty -player" who enjoy the dynamic intricacies this opening provides regardless if one is a chess expert or not.
most chess players are afraid of the amount of theory in mainline openings. But I would still recommend to play sound mainline openings since there are more patterns to learn, more structures to understand and therefore a good choice for people willing to improve their game. You don't necessarily have to play the Najdorf. The Taimanov for example is less theory heavy and also seems to be quite solid.

I decided to play the Sicilian in my breakthrough tournament to enter the expert class. Tied for first to get a 2000 floor before my official rating changed. In short, 'twas a big mistake. Rift in spacetime among other inconveniences.
Better play the Scandinavian if you don't want to end up like me.

Sure, anyone can play the Sicilian. That was never the point anyone was trying to make. But if a class player wants to improve, there may be better openings than the Sicilian for them.
Actually, that is the title and whole point of this thread!

The Sicilian's standard first few moves exchanges White's center d-Pawn for Black's c-Pawn and begins a process that usually leads to a strong Q-side position for Black. Consequently, even if you don't play the book moves for the Dragon, Najdorf, etc. you should be able to achieve a VERY playable middle game for Black even if you're a club-level player.
Of course, that means NOT memorizing reams of opening moves but studying the ideas behind the Sicilian and understanding opening principles strongly!
Personally, as White, I tend to play the 2 c3 Sicilian, both to avoid someone very comfortable with the standard Sicilian variations and to avoid giving up my d-Pawn for a c-Pawn. It also seems to me that the Closed Sicilian, 2 Nc3 and avoiding a very early d4, gains space for White but I don't do well with it - it was a favorite of Spassky and Smyslov, so it should work against non-masters!
Around 2010, IM John Watson wrote, "... For players with very limited experience, ... the Sicilian Defence ... normally leaves you with little room to manoeuvre and is best left until your positional skills develop. ... I'm still not excited about my students playing the Sicilian Defence at [the stage where they have a moderate level of experience and some opening competence], because it almost always means playing with less space and development, and in some cases with exotic and not particularly instructive pawn-structures. ... if you're taking the Sicilian up at [say, 1700 Elo and above], you should put in a lot of serious study time, as well as commit to playing it for a few years. ..."

Around 2010, IM John Watson wrote, " ... if you're taking the Sicilian up at [say, 1700 Elo and above], you should put in a lot of serious study time, as well as commit to playing it for a few years. ..."
That's true of any opening.

This is what will happen if a non-expert plays the sicilian

The thing with sicilian is that there are many many variations and almost all of them are quite good for both sides. The sicilian games are generally dynamic and positions have an imbalance. These characteristics of sicilian means that you would need tons of opening preparation and good tactical and positional understanding to play it really well. And the game could end really fast if some little mistakes are made by either side. Those are good reasons to avoid sicilian opening.
But, here are reasons to play sicilian:
a) you can't really avoid sicilian. Sicilian is a very popular opening at all levels and you are likely to face lot of variations of sicilian as white player if you play e4. And to understand how to play against an opening as white, its better to play it as black.
b) sicilian could be the ultimate teacher (with all its complications and stuff) for amateur players wanting to improve. But, you have to put in a lot of time and effort in opening prep.
c) All said and done, sicilian gives black a pretty good chance compared to many other openings. Because of the complexities of sicilian, both sides tend to be under-prepared and make mistakes thus equalizing the odds. In other openings(against e4), it is much easier to prepare for a white player because of lesser variations. So, the more number of variations makes it difficult for both sides and increases the chances of winning or drawing for black.
At what rating should one start playing sicilian? I don't know. I think everyone initially starts with e5 against e4. At some point, you start feeling that e5 is just not giving you the results and you want to switch to some kind of assymetric defence against e4. I think that is a good time to switch to sicilian. Though, scandinavian also seems like a good choice to try at that stage.

@Ashvapathi,
your answer doesn't address the key point, which I made quite a while ago:
the Sicilian can be played by anyone, if their primary goal is to have fun.
if yourgoalisconsistent improvement to become a master, then the Black side of the Sicilian should be left for later in your chess development. I'veexpounded on why that is the usual recommendation of chess coaches before, but just read what Greg Shahade wrote in Chess Life's online magazine for more info.
Only three openings worth considering 1.c4 as white 1...c5 against the king pawn and the Gruenfeld against the queen pawn, all else are noob. Sicilian is a way of life!