Why is having believers of all ages and interests meeting together, so controversial in the modern church?

Did the idea that a good church must separate everyone by age and interest come from the Bible or elsewhere?

The Bible says:

Eph. 4:1 I, therefore, the prisoner of the Lord, beseech you to walk worthy of the calling with which you were called, 2 with all lowliness and gentleness, with longsuffering, bearing with one another in love, 3 endeavoring to keep the unity of the Spirit in the bond of peace. 4 There is one body and one Spirit, just as you were called in one hope of your calling; 5 one Lord, one faith, one baptism; 6 one  God and Father of all, who is above all, and through all, and in you all.

If we are one family of God, united by His Spirit and we told to endeavor to keep the unity of the Spirit, why is the first question people ask about a church usually something about what programs they have to separate believers?

Do you have a good children's ministry?

Do you have a good seniors ministry?

Do you offer a sports ministry?

Do you have a ministry for....

Ok, how about: Do you have a time when those who believe, of all ages, "The Church", can be together to worship, pray and learn God's word?

"Scripture taken from the New King James Version®. Copyright © 1982 by Thomas Nelson, Inc. Used by permission. All rights reserved."