Why? It's so inefficient and provides a poor user experience.
Power users and developers will understand the need for it to download the entire 3.5GB+ blockchain, however the average Joe will not.
I understand that the 0.8 ultraprune client will reduce first run time to 30 minutes, however that is not enough. Until the official client is snappy enough and has a sleek & sexy interface (think Electrum on MacOS), I will be recommending Electrum/Armory or web wallets like BlockChain/Coinbase to people who ask me about Bitcoin.
It is important to consider the needs and desires of the user before recommending anything. If I told you I was thinking about purchasing a vehicle, and was looking for some advice about which type of vehicle to buy, would you recommend a coup, sedan, SUV, pickup truck, or sailboat or motorboat?
To just arbitrarily recommend a wallet (or vehicle) is a silly thing to do. You are assuming that the person asking for advice will be using that wallet (or vehicle) in exactly the same way as you.
The better options are to either:
Take the time to figure out exactly what the person asking needs/wants, and then recommend based on that information.
or
Assist the person in learning the benefits and shortcomings of each option so they can make an educated choice for themselves.