Developers are quite worried about testnet gaining value on your swap exchange, it's against the motive of the testnet ecosystem, although faucets are not meant to be abused, and users may not get the number of token they need through faucet services buying to hold and trade later is much more like the main net this time. Though it's nobody's business, but people with the volume of testnet coins like yourself give it out and advice the receiver to return it once they're done testing their apps.