Your problem isn't with marriage, but with the fact that marriage entitles people to pay fewer taxes than an unmarried couple. It's a perfectly legitimate complaint, and it's an interesting issue.
It's not ONLY that "marriage" entitles people to pay less in taxes (which is certainly true). It's also that unmarried individuals and couples are forced to subsidize the benefits received by the "married."
For example, when an employer is compelled to provide insurance coverage for "married" spouses, this reduces payroll and salaries across the board, even for those who are single or "unmarried." Which is not to say that employers are always forced to do it, but sometimes they are.
As another example, "married" spouses who have never worked a day in their lives are eligible to draw social security and medicare benefits beginning the day they turn 65, whereas "unmarried" individuals who have contributed nothing, get nothing. And who pays for that additional coverage for "married" people who don't work and who don't contribute to the system? People who choose not to participate in the marriage scam.
Why are married couples taxed less than single individuals (or individuals whose relationship isn't formally declared with the government)? My guess is that it's a factor to encourage and help with child-rearing.... Should the tax break only be given once a couple has at least one child? It might alter the incentive behind the tax break a bit, but it's an interesting change to consider.
It's always hazardous to subsidize people to pay for things that are mostly of their own doing (e.g. having kids). The risk is, that you end up incentivizing behavior that is more or less irresponsible (e.g. having kids to get welfare).
However, this *certainly* makes a lot more sense than the idiocy of mandating benefits solely based on "marital status" or whatever private nonsense the government wishes to invoke.
I think socially we ought to be way beyond the point of "sit on a guys c*ck, get special perks and benefits courtesy of the government." So yes, now we have yet another special interest group trying to find a way to hang off the proverbial teat... go away, please.
(The other interesting consideration is that whenever "gay marriage" and tax break complaints come up, you don't hear any complaints about childless heterosexual marriages...)
I think this is because, for a great many heterosexual couples, in the past one always assumed this was because of an infertility issue (which may or may not have been the case), and the woman couldn't find a job. Point taken though -- it makes no sense, and needs to be changed.