Simple.......

IT is, because IT needs to be.

You have illustrated the problem well. There are at least 3 its.

1. IT - Almost exclusively "Information Technology". However some idiot screwed up because of his/her bloody ego and now also an audio file format used by those wankers Impulse Tracker.

2. .it - The domain name for Italy: A boot shaped European appendage (a.k.a. peninsula) inhabited by a group of people who for some bizarre reason prefer to speak Italian more than English. This is possibly due to eating too much pasta, parmesan cheese, and/or tomatoes, but this isn't certain. It could equally be the mozzarella cheese or other thing with all sorts of redundant consonants.

3. It - Third person pronoun denoting an inanimate object, idea or one without gender, capitalized when at the beginning of a sentence or after a colon: Like paper, rocks, and (ahem) unfortunately you. Well look, you're the one whose 'lap' disappeared...and that's where it's located.

4. "It" is also the word used by college/Uni freshmen (almost exclusively) instead of the word 'intercourse'. An example might be helpful (for one whose lap 'disappears'): "After doing it, Jim and Bessie dozed off." For some odd reason people also seem to widen their eyes and open their mouths when saying 'it' in this context.

Doc, I think you're too preoccupied... maybe even obsessed with it in its various forms.

And I notice that you left the most important it 'til last... but then, most people tend to leave their favourite bits 'til last.

As in 'last but not least'... and there's an emphasis on the 'not least' bit because it is waaaay too important to be least.

In this case I need not ask 'why is it?

The answer is bloody obvious... doc has been on the horny goatweed again.  Or is that still?

And the reason Italians prefer to speak Italian rather than English is because their favourite letter is A, and it gives them the excuse to add it to most every word they use... 'lika tha time a he wenta to tha docta about his a hernia'

So why is it, if you have a French dictionary it's full of French letters?

The correct answer depends on one's particular (or in your case, peculiar), bent:

a. Because.

b. Why not.

Not just her...Sophia Loren in "Boy on a Dolphin" and Bo Derek in "10".

Amazing we all didn't die of testosterone toxicity.

Naughty err...nighty, night Mark. 

Now there's a puzzling one, Philly... an enigma wrapped in a mystery, so to speak

Why is it you always ask the most difficult questions?

For those who didn't catch on, the object of this thread is to try answer the person's question before you while asking one of your own 'why is it's'.

Can be a serious question or something just for fun.