I understand that a CS degree would've made things much easier on getting a job, and I would've been offered a higher salary as well, I'm sure. As I said, that's why I don't ask for sympathy, I know full well that my path is probably the less traditional one. But even so I had plenty of hours of programming on the courses I took -- C/C++, Digital Electronics (programming FPGA boards, tinkering CPUs/APUs), not to mention that I had an 18 month internship -- which is where I learned about web dev -- and I designed two relational databases in previous part-time jobs. All of this came up during my various interviews, and I wasn't ever given a callback until I was. So I'd say there's an abundance of candidates, even if there's potentially a skill gap on those candidates it's a gap that's easily bridged, but too many employers don't want to invest any time training in their employees, which shouldn't be the norm in any industry, but is somehow acceptable in our current tech industry.
I know people with math, statistics and aeronautical engineering backgrounds who've worked at Google and Microsoft. I'm sure physicists would fit in too.
Second, I, and apparently several people you interviewed with, would claim physics isn't even peripherally related to web development. If you were writing simulation software or FEA software, I'd completely agree. But where's the connection to web development?
Finally, I was making an analogy, not comparing web development to being a doctor.