(My repsonse to the reasons will be in the pink colour)

Hamlet Not optimistic or uplifting. Characters not appealing to modern pupils as royalty is no longer fashionable (Okay, there is a reason why it's called a tragedy.  And about the comment on it not being uplifting?  Well, have they actually ever READ the play?  It's freakin' hilarious.  You just have to look carefully.  For example:
KING CLAUDIUS:Now, Hamlet, where's Polonius?

HAMLET: At supper.

KING CLAUDIUS:At supper! where?

HAMLET:Not where he eats, but where he is eaten: a certain
convocation of politic worms are e'en at him. Your
worm is your only emperor for diet: we fat all
creatures else to fat us, and we fat ourselves for
maggots: your fat king and your lean beggar is but
variable service, two dishes, but to one table:
that's the end.

KING CLAUDIUS:Alas, alas!

HAMLET:A man may fish with the worm that hath eat of a
king, and cat of the fish that hath fed of that worm.

KING CLAUDIUS:What dost you mean by this?

HAMLET:Nothing but to show you how a king may go a
progress through the guts of a beggar.

KING CLAUDIUS:Where is Polonius?

HAMLET:In heaven; send hither to see: if your messenger
find him not there, seek him i' the other place
yourself. But indeed, if you find him not within
this month, you shall nose him as you go up the
stairs into the lobby.

KING CLAUDIUS;Go seek him there.[To some Attendants]

HAMLET:He will stay till ye come.
[Exeunt Attendants]

(IV.iii. 16-40)

And of course we can all remember the hilarious attributes of Act 2, scene 2, in which Hamlet mocks Polonius and the latter has no clue what is happening.  After all, Hamlet calls him a "fishmonger" (II.ii.174) and he doesn't get it! 

I just don't understand the way some people think.)

King Lear Not exciting. Full of violence and despair. Ridiculous and unlikely plot. (Okay, so I hated this play, but it is still worth a read.  I can't believe that it was labelled as "not exciting".  When you have a character named "Edmund the Bastard", I expect a fun play.  Plus there is always the necessary disguise trick used.  It's interesting.  It's worth the opportunity to study it.  And of course it's about violence and despair.  IT'S A TRAGEDY!  Plus, there is a WAR going on.  Also, this play has a really interesting torture scene in which Gloucester gets his beard plucked and his eyes ripped out.  You can read more in depth about this in Act 3, scene 7.)

Julius Caesar Sexist because it elevates men (Wow.  A play that takes place during the Roman Empire elevating men?  It's a part of the history of the world.  Get over it.)

Antony and Cleopatra Racist and undemocratic (Now this just makes me giggle.  Okay, so they call her a gypsy (I.i.10), but still.  This isn't a hugely racsist play.  For the most part, they just call Cleopatra a whore.  It's funny.  Oh, and about the fact that it's undemocratic, she was the Queen.  She made the decisions.  As for triumvirs, in all honesty they really weren't worth their weight in gold.  None of them did anything.  They weren't all powerful.  Mark Antony gave in because of a woman.  How sad is that.  It's no reason to ban the play though.)

Othello Racist and sexist. A bleak and pessimistic tone (And back to the fact that it's a tragedy.  It's depressing for a reason.  And racist because of the fact that it was wrong for a black man and a white woman to be together at the time that it was written.  It's all in the context people.  It's called using your brain. 

Here is the link that I found this information at: http://books.guardian.co.uk/news/articles/0,6109,474398,00.html

People make me so mad sometimes.  I just wish that people could understand Shakespeare.  It isn't that it's bad or boring.  It's just that people that don't take the time to look at it carefully and find the joy in it.  You can look at all the comedies in the world to find that joy, but when you find it in the bleakest moment of a play, it's even more special.  When you need that laugh to break the tension, you know that you are watching/reading something real.  And it's so cool to be a part of that experience.  Moreso than just reading the frilly plays that leave everyone all happy at the end.  And I'm not saying that anything is wrong with people liking the comedies.  I love comedies.  But I love my Hamlet.  And no one can mess with that.  The real magic of Shakespeare is being able to find that passage in The First Part of King Henry the Fourth that makes you laugh.  It's in Falstaff's crude behaviour that you find the funniest lines of the most boring of plays.  That's the important thing to look for.  Look for the good.

And now to finish up, my Shakespeare prof would kill me if I didn't do this.  Here is my "Works Cited":

Bevington, David. The Complete Works of Shakespeare (fifth edition). Pearson Longman. New York, NY: 2004

(I think that I did the right.  I didn't have my other text in front of me to tell me if I fudged it up or not.  I probably did.  I don't think I ever did one correctly for the good Dr.)