Karwa Chaut is good as long as it is done by people with full heart and soul, otherwise it loses it's purpose.
Anyways this debate will go on and on, and its ultimately trivial to impose our views about this.
A person who sees this as a patriarchal custom, is partially correct. Because this is a patriarchal custom. They may be those cases where women do this unwillingly, just because of social pressure. And out of fear and guilt that them not following it, might result in the demise of their husband, they unwillingly do it, and ultimately adjust to it.
But the other side of the coin is, there are also many cases where women do this out of love for their husband, and than there are many supportive husbands who also participate by fasting themselves, praying for the his wife's long life.
There are many husbands who don't want their wife to keep this, but wives do anyways, because either of love or fear.
The points raised by both parties is correct, the problem arises when the people start thinking the other party as either regressive or anti-Hindu.
And no I am not saying everyone in the respective parties are doing it with pure intentions, yes there maybe some regressive people and some anti-Hindu people in either parties. But just because some one is in favour or against Karwa Chaut, we cant assume and accuse people.
See, customs and festivals shouldn't be forced, it is true. But we shouldn't be criticizing those who celebrate it out of love and devotion just because there are cases where they're forced. And we shouldn't also turn blind eyes to the injustice happening just on the name of the religion/festives/customs.
Yes Karwa Chaut is a festival where a woman fasts and prays for the long life of her husband, and question arising why only wives keep it, and why not husbands too. And that is a valid point, the time when the origins of the festival was found, it was celebrated for very different reasons, which is kind of outdated in today's time. And some modifications is required and yes there are many husbands who have started to keep fast themselves too, which is a good start towards equality.
See obviously festival has nothing to do with life expectancy, but than again every festival has no meaning and are just functions for social gathering. So calling out for total boycott is silly, because you can stop a Teej or KC, but tomorrow a new festival will comeout. That is how it is, humans are social animals who find many great ideas with stupid premise for socializing. So we need to find modifications and upgradation of the customs and festivals, because trying to kill something which isn't exactly harmful is just an immature action, which eventually leads to stupid consequences like divided people fighting over something as futile as a bloody festival.