I've noticed some liability waivers include language to the effect of "I have had an opportunity to seek legal advice before signing." You don't have to get your lawyer to actually sign off, or even affirm that you talked to one, just represent that you were not put in a position of having to make a snap decision without the chance to run it by a professional. Of course, that's usually not true; even when I book in advance, I rarely get a copy of the waiver until I'm on-site ready to go. At the earliest, I get it right after I've paid. So while part of me likes the idea of self-certification of fitness to dive, part of me thinks that would result in a lot fewer people actually even talking to their doctors, and that might be a bad thing. After all, just look at how many people, having never actually consulted a lawyer, believe those waivers aren't enforceable anyway.
Like a lot of people, I was diagnosed with asthma as a child but grew out of it; I haven't had any symptoms whatsoever since well before I reached adulthood. But the RSTC form asks if you've "ever" had it, which I think is ridiculous. I told the truth a few times and got my doctor's signature, but other times I've just said "no." I would much rather sign something that says I understand the risk and accept it, and release everyone on earth from any liability forever if I get hurt or killed while diving due to complications from asthma.
My husband, on the other hand, has a history of spontaneous pneumothorax. When we were planning our Caribbean honeymoon before I was certified, we decided to try scuba diving. We'd each dabbled in it before; I did a discover dive ten years earlier, and he'd taken a course in high school (prior to his lung collapse). So we were each filling out the forms, but his doctor wouldn't sign off on his, and urged him to see a specialist. The pulmonologist was willing to run some tests to get a better sense of the risk, but warned him that they couldn't rule out the possibility of additional blebs too small for the machine to pick up, any of which could kill him underwater. We decided to stick to snorkeling. Had we been able to sign away the risk without a doctor's input, we probably would have. And maybe that would've turned out fine. Or maybe I'd now be a widow.
It's tempting to throw everything at the feet of personal responsibility, but most people just don't have enough information to properly weigh the risks. What I would really like to see is a slight modification of the forms to better reflect the latest medical understanding (I think the alarm over a history of spontaneous pneumothorax is better supported than the alarm over a mere history of asthma.) Perhaps the form could also be modified so that the physician doesn't certify that the diver is fit to dive, but rather that they have discussed the risks with the patient/diver.
The way I envision the form is to lay out the medical dangers of diving in layman's terms. This encourages the diver to seek out proper evaluation for critical issues like your husband's spontaneous pneumothorax. That would be one of the listed critical (diving prohibited in all but a few cases) conditions. Without knowing this before signing the form the layman probably would not know the difference between your childhood asthma and his long ago spontaneous pneumothorax. Both seem resolved to you.