From the 1960s into the 2000s, Shea Stadium defined the Mets. It was scrappy, it was far inferior to Yankee Stadium, but it was colorful and it united the fans into a 40,000-person family.
In 2009 when the Mets moved across the parking lot to Citi Field, they were spiraling down into a nose dive that no one could stop. And the spacious, expensive stadium they constructed with a black wall and green seats was only making things worse.
Sure it was beautiful architecture and had amazing lounges and clubs, but that has never been the Mets. The best thing Citi Field had was its compact feel and lack of extracurricular activity. Everyone was in their seats for all nine innings, cheering on the team that they were practically sitting on top of.