The Mets are a terrible defensive team. The execrable bullpen is a more overt culprit in explaining how a team with expectations could begin the holiday weekend with a better record than only one other NL club.
The bad glove work, though, has contributed to undermining the pitching. Statistically, the Mets were fourth worst in the majors in turning balls put into play into outs. Tacitly, there may be a cascading negativity. One member of the team told me he thought pitchers were impacted in pitch selection and how they attacked hitters because they were concerned in letting the ball be put in play.