I think people have been failing the institution of marriage for a long time - see the surname Fitzroy for more on this - I think the tacit social support structures buoying up those people who wanted to deviate from the way marriage was intended, have given way to an 'opt out' system, which makes it conceptually redundant. People have always failed at marriage - the institution has held together, now the people are beginning to (legally) dismantle the support structure.