It has long been held that preachers can't count. I suppose it's because they usually overestimate the size of the attendance or count the unborn babies as present.
All humor aside, it is true that preachers do place a certain importance on "numbers" because numbers reveal certain things about a church.
1. Numbers Reveal Commitment
You may have 1,000 people at church but if this represents only 50% of your members, what you see is a half-hearted commitment. It would be more interesting if we measured what percentage of members and their families attended regularly. This would demonstrate more accurately the type of commitment that actually exists.
2. Numbers Reveal Potential
Small churches are great and God has no favorites according to size, but big numbers in the pew and in the plate are a sign that a church is ready to do big things. Small churches concentrate on staying alive and establishing themselves, big number churches have the resources to make things happen outside the walls of the church building. When 500 people have a mind to build or save - they can do it in a big way.
3. Numbers Reveal Christ
Some may balk at this statement but when a church is growing, people pay attention. Little churches that stay little for decades while others around them grow are not going to impress their neighbors that they are the church of Christ because Christ's church was a growing church!
I don't know where this thing about preachers and numbers started - maybe they saw that in the book of Acts the Holy Spirit numbered the ones that had been baptized and realized that God is counting too!