There are many similarities between using CSS hacks and lying.
First of all, what is a CSS hack? A CSS hack is a means by which you can get different browsers and browser versions to see and render your stylesheets differently so you can give them different directions (ironically though it's normally done to achieve pixel perfect cross platform web pages). They are also mostly done for Internet Explorer (which for some reason refused to implement standards based CSS until recently).
CSS hacks mostly exploit bugs in a particular browser such as the Star HTML hack. This hack was used to get code to run in IE6 and lower in a different manner than other browsers.
IE also introduced conditional comments which allow you to add an extra stylesheet to "fix" any CSS issues. This is not technically a hack, but it does require you to write and maintain extra CSS.
There are also more subtle types of hacks to make up for some things that are missing in IE like the IE min-height hack (which adds min-height style functionality to IE).
So why is using a CSS hack like lying?
Well, when you tell a lie not only are you telling an untruth, but you are essentially telling one person a different story than someone else. This is not admirable behaviour, but you can probably get away with it, once or twice. However as you have no control (mostly) which clients can see your site this is akin to lying to someone whilst there are other people in the same room. After telling the lie you then have to sneak over to all the other people and tell them a story and hope the first person doesn't cotton on.
Often with lying (as with CSS hacks) telling one lie requires you to tell another one (and to keep track of all the lies you tell). You then end up with a snowball effect wherein you lose track of what is true and what is not and you end up with more code than you ever needed.
Why use CSS hacks in the first place?
Because not only do these little CSS browser differences open hacks, they often are the cause for rendering differences between the browsers. There is a temptation to therefore use other hacks to fix these differences.
So there is often a judgement call to be made as to how far you can push a hack, and pile hack upon hack. At some stage compromises need to be made in the design.
So basically, I am not saying one should never lie, in web development (like in life) there are times when you need to use hacks and there are times when you need to lie. Just be careful not to do it too often (and document it carefully).