People are judged by what they do, not by what they say. If the Church solemnizes marriages between divorcees, no number of affirmations about lifelong union will cut any ice. For every person who reads and believes what bishops say, there are hundreds who take no notice of clergymen, but would only know that a niece, a neighbour, or a film star got married in Church after a divorce. The point of the existing rule is very clear, and easily understood even by those to whom it denies a church wedding. Once the rule is abandoned, however, the Church is faced with the invidious task of selecting some, who are to be allowed a church wedding, and rejecting others, and then with the impossible task of reconciling the latter to its decision.
Bishops are busy men.
To grant or withold permission for a church wedding is inherently contentious. To go into the question properly would take a lot of time they could ill afford. There would be strong pressure, in view of the other calls on their time, to devote less time to remarriage pleas. No' is the difficult decision to reach. Because it disappoints the applicant reasons why he cannot have what he wants would need to be thought out, and if reasons cannot be thought out through lack of time, the only safe answer is 'Yes'.