I am so sorry that you see things this way.
The institution of marriage is getting a bad rap by people who want to change the fundamental underpinnings of our society. They are succeeding in so many ways: abortion, gun grabbing, forbidding prayer, flying planes into buildings, etc.
It is so sad to see this happening.
Your analysis is superficial. What has happened is that the world has very literally changed. Marriage existed a century ago to fulfill literally dozens of functions, many of which are obsolete now. That isn't to say that marriage is bad, it is just that it would be unreasonable to expect it to function identically today to how it functioned a century ago because some of the old contexts simply don't exist any more.
The problem isn't with marriage per se, it is with how marriage has changed to suit the changing context of its existence. I see two big flaws in the way these arguments often play out. First, there are those that want marriage to be exactly the way it was a century ago. Second, there are those that think the way it is now is just fine. Both positions are flawed on many levels. The fact is, the institution of marriage and all the social structure that surrounds it does need to change from what it was a century ago to accommodate the substantially different context of its existence. The problem is that the changes that have taken place have been very much in the wrong direction and have done nothing to accommodate the clean and useful evolution of marriage.
As I see it, there are three dogs in this race: what we used to have, what we do have, and what we should have. People need to rigorously analyze and criticize the various outcomes or the problem will not go away. There needs to be a third way, and it would be far more constructive if we spent time actually figuring out what marriage should be in a modern context.