Disagree all you like. So much easier in your home country, no proof of money transfer, no onward travel needed, less paperwork and no time wasted on an extra visit to Immigration, 90 days on entry.
Health insurance is for the Non Imm OA not the O. Saves a trip to Immigration, no need to prove transfer of 800k, easier to get a Thai bank account, no onward travel required, much easier getting the O before you arrive.