Why are parsnips sold pre-clipped? In Swedish and, I'm led to believe, British supermarkets, parsnips are often sold pre-clipped. Topped and tailed.

If I have a choice, I prefer to buy my veg with a few leaves on so I can see how fresh it is. So I have rather cynically assumed that this is done to hide the age of the product. Whether or not this is the case, I wonder why the same trimming service is not extended to carrots.

Anyone able to shed some light?

Update: Quite often just the tip of the parsnip is trimmed. This appears to be a global phenomenon; here are some parsnips from an Australian market.



The two answers I've so far received are good, but don't explain why the tip might also be trimmed.
In the US, carrots are normally sold topless too.

I do understand the desire to see those fresh green leaves on it, but in fact, they're not helping. Since they're still alive, they draw nutrients and water out of the root, decreasing what's left for you. This means they may actually be worse than ones that had the tops left on them, especially if they've been stored for a while. They'll have less flavor and won't be as crisp. If you do buy them with the tops still on, it's a good idea to at least trim them before storing.