Default transliteration · Kevin
凯文 is not a name a native would pick
凯文 is what you get when someone looks up Kevin in a pinyin table. 陆克文 is what you get when someone builds a name: surname 陆, given name 克文. Same English. Opposite verdicts.
凯文 is a spelling
凯 can appear in real given names. 文 is everywhere. Together, as a two-character blob with no surname, they are the default Kevin. Natives hear 'the English name Kevin, written in Chinese,' not a person from a family named 凯.
陆克文 is a name
Kevin Rudd's Chinese name is the public example. 陆 is a 百家姓 surname. 克文 uses characters that show up in actual given names (克强, 文). It echoes Kevin without becoming the table row. This checker is built to tell those apart.
Teachers pick the table
A teacher with thirty students and ten minutes will hand out 凯文. That is not malice. It is the Xinhua pipeline. Kill the pattern, not the person who received it.