Huh? Medical professionals, lawyers, accountants, actuaries, etc. are all license-based professions. There is a very good reason for this, because a big part of the job is about adhering to important laws, regulations, ethics, etc. A big reason for the non-reciprocity (US-trained doctors cannot practice in many other countries, for example) is that these laws and regulations are not universal. There are some reciprocity arrangements in place, but given how bureaucratic the licensing system is, it is just hard.

You don't have any justification for making programming a license-based profession. You wouldn't want that even if you are an American citizen. It makes things significantly harder and more arbitrary when you have licensing requirements (just look at how hard each of USMLE, CPA, bar, CFA, etc. are, even for US citizens). Engineers, for example, can be licensed, but apart from public contracts in civil, mechanical, or electrical engineering, few employers care if you are a 'P.E.'