I've gotten much better about charging rates I'm comfortable with, and finding clients that a) can afford it and b) find value in what I do at those rates. It would actually be nicer to do 'value-based' pricing, vs hourly, but it's not something that both parties are usually able to agree on. Unless you know a particular industry well, it may be hard to understand the full value of the work you do. Even then, the company may much prefer to pay hourly or much lower rates, simply because they can probably find someone else to do it.
With medical and legal professions, the licensing/regulation creates a large barrier to entry, and people have to go to those professionals for certain tasks. You can represent yourself in court, for example, but it's often frowned on, but you generally can't prescribe yourself your own medication. With software, no licensing/regulation exists, so there's generally a much broader range of skills and value in the marketplace, which dilutes the value perception many people have.
Agreed on the age thing. As long as there's a youth-obsessed focus in the software world (and I think it's done just as much by us inside than by the outside world) it'll be hard to get the respect we'd like as a profession, simply because most people don't treat it as a career. Would you rather use a 22 year old lawyer, or a 52 year old lawyer? How about a 22 year old developer vs a 52 year old developer? :)