Don't disagree with any of the above.
I hate saying it but if you offer cheaper/free services there is a small segment that will then not respect you. I've done it. I still do it, but I only allow patients to not be charged or lower rates if I'm confident they're telling me the truth about their dire straights.
I also feel that being a professor, working in Medicaid offices for years was my own payback to society. I earned a lot less in those roles than I could've in private practice.
I still do allow patients to not be charged or lesser rates but usually only if I've had the patient for over a year, feel there's a level of trust, and their story that I know very well gels together with their inability to pay.
I remember the exact day I when it crystallized I couldn't let patients go as much. A patient who grossed over $ 1 million in his business a year kept telling me he couldn't pay, and I already let him go a few times. I did some looking into this guy, saw a court document that showed his finances, and told my assistant never to let him in again unless he paid. From that day onwards I never did pro-bono work unless I already had the patient, already knew them well, and the person told me they were having some serious problems paying.
Add to this be careful. Doing pro-bono could make you look worse. In addition to some possibly interpreting you as a lower-rung doctor, let's say for argument's sake the person you are providing pro-bono services to is a very sexually attractive person. IF any legal issues happened someone could interpret your pro-bono benevolent intents in something other than what it was.
Another area where I at first wanted to be beneficent was doing volunteer work for the VA. I used to work for a state hospital with the same exact setup as the VA and used to work in a VA 2-3 days a week not as a VA employee but as a forensic examiner for the court. There were loads of inefficiency that I thought wasn't the result of good intent but rather ineptitude. While I strongly support veterans and wounded warriors I felt this was an enabling problem by helping an institution that wasn't doing it's own efforts to get it's own house in order. I still remember while in a state hospital the CMO giving me the worst patients of the other doctors who didn't do their jobs, I'd get them better, then they'd transfer them back to the bad doctors who then got them worse again against my idiot-proof directions. E.g. "Dr. X, patient was tried on 5 meds and the current medication regimen improved the patient's GAF from a 30 to a 65." Then within 1 day the patient was placed back on their previous medication regimen by the prior and now current doctor. While I was proud at first to be given the honor after a few months of it I noticed these other doctors were seriously just lazy and not doing their jobs. I had one doctor even tell me they intentionally worked at the place so they could have a do-nothing job. Great I was enabling this problem instead of the management putting these people in order.
Of course not all VAs or state hospitals are the same and not all staff members in such institutions are bad, but I had my own fill of it.