DEAR JANET MEFFERD:
Ask any Straight couple why they choose to marry. Their answer will not be, "We want to get married so that we can have sex and make babies!" That would be absurd, since couples do not need to marry to make babies, nor is the ability of even desire to make babies a prerequisite for obtaining a marriage license.
No, the reason couples choose to marry is to make a solemn declaration before friends and family members that they wish to make a commitment to one another's happiness, health, and well-being, to the exclusion of all others. Those friends and family members will subsequently act as a force of encouragement for that couple to hold fast to their vows.
THAT'S what makes marriage a good thing, Gay or Straight.