Why is Mike Pelfrey in the majors?

After today's debacle, Mike Pelfrey has a career 6.43 ERA with 19 walks and 19 strikeouts in 35 innings. He has a bad ERA, a bad strikeout rate, and a bad walk rate. I know it's a small sample size, but there's nothing in his line to indicate that he's ready to pitch against major league hitters. Heck, his spring training stats were almost as bad: 5.48 ERA with 3 walks and 5 Ks in 23 innings. I think the Mets gave him a starting spot because of the low ERA he had after his first few spring starts, but they ignored the amazingly low strikeout rate, which was a clear sign that Pelfrey just isn't able to get his stuff past major league hitters yet.
Pelfrey has about 100 career minor league innings. It's pretty clear that he needs a little more seasoning before he's ready. I think Pelfrey would be better served by getting that seasoning in New Orleans, and I think the Mets would be better served by not giving away every fifth game. Jorge Sosa has been lighting up AAA so far and has a career 4.54 ERA in 74 major league starts. Pelfrey's still the long-term solution, but Sosa (or Vargas or Park) will give the Mets a better chance to win right now.