When I was married to my wife, her brother was not worthy to attend. Also, My father did not have a recommend to attend, and my brother was on his way out of the church and attended in less than respectful circumstances. None let me know out of fear they would “spoil” my wedding, but all were excluded in some fashion.
After having left the church, I felt the sting of being excluded from the ceremony as I became an unasked babysitter. The reception was nice, and how much greater the bride’s joy would have been to have everyone included in her public union. A private union for worthy church members thereafter could then be done with just as much pomp and circumstance.
Social pressure to perform a temple wedding doesn’t only come from individuals outside the church. It also makes people who are young, unworthy or otherwise not yet members isolate themselves at a time that should be focused on being united as a family.