Fang, you are simplifying the offense by relating to one aspect, Runs, as a measure of accomplishment. They are also 7th in the NL and 7th doesn't fit into the playoff format.
You may be right, I might be oversimplifying, but in a game where the sole purpose is to score more runs than the other team, the simplest test of team offense and team pitching/defense are runs scored vs runs allowed. We all know there are many paths a team can take to accomplish those goals. On offense, small ball (my preferred way - Sandy doesn't agree) or HR is another choice. Just like for proficient pitchers, fireballers rely on Ks, guys with slick movement get the job done through weak contact. Either way you choose, score more, give up less, the simplest version of baseball.
Mets have slid to 12th in the league in runs scored. (From 8th) since we started this conversation.
Mets are 29th in the league in runs allowed.
Using that simplest test, is it any surprise they had a losing streak as their run production fell? But as we know, TdA/Cabrera/Cespedes all recently injured and Duda just back hasn't adjusted back to MLB pitching, so is it much of a surprise the offense has stalled? That is 50% of your projected offense out for a significant portion of time. Yes, he relies on the HR, but when guys who will hit you 90 annual HRs get taken out of the line up, your run production is going to falter.