Ever worked with someone who was only there for the pay check? They didn’t care about the job, or the people around them; they showed up, clocked in, did as little as possible to keep their job, and clocked out.
Ever caught yourself having the same attitude about your marriage? Do the minimum necessary to keep her from leaving, or to keep her from going ballistic, and nothing more. Most of us fall into that temptation on occasion (I certainly have), especially when we are stressed, tired, or otherwise overwhelmed. The important question is how often we give in to the temptation, and how often we reject it.
I’ve noticed clock punchers suffer eventually. Sometimes the minimum to keep the job day-to-day is not enough to keep it long-term. If there are cutbacks, the clock punchers get fewer hours, and are let go first. In the same way, doing the minimum in your marriage will catch up to you at some point.