Marriage may or may not be a good thing.
Where 2 people marry and they get along well and have a happy marriage, it is a very good thing - my wife and I are in that category.
Where 2 people marry and don't get along, then it can be a bad thing for themselve and any children they may have.
A few people I know should never have married, just like a lot of people I know should never have had kids.
Marriage, in and of itself, is neither good nor bad. It is a legal and moral relationship. Some are mature enough for it, but in our ophraphied society, an increasing number aren't and will never be.
The number of divorces, the number of people who never get married,the number of spouses who cheat on their partners would suggest that the author of the article may have rose colored glasses on.
In spite of the failure of some to marry the right person, work hard enough to make their marriages work, humble themselves enough to be a Godly spouse, etc. etc., MARRIAGE IS STILL A GOOD THING.
Your argument is like saying that freedom isn't a good thing because all people aren't free. Failure doesn't make the concept wrong.
And in both the cases of marriage and freedom, the concept came from God, and is, therefore, a GOOD thing.