We believe that altar calls are a bad idea.
They promote a false sense of security, by giving someone a faith in their response to an altar call years ago, instead of faith in Jesus Christ alone. People are always content to look to something else, particularly some action they have taken, instead of goin straight to Jesus and having direct dealings with Him.
Secondly, there is nothing magic about coming to the front of the church. If God the Holy Spirit is having dealings with a person in their chair, then that is exactly the place/time that they need to seek forgiveness and have dealings with Christ. They should not wait for the end of the service and an altar call.
Third, it can promote a damning sense of pride. Self-explanatory. "The heart is deceitful above all things, who can know it?"
There are many, many people who are very happy to give someone counsel about their response to a sermon. If they would like counsel, they don't need an altar call to get help.