I had an older friend in pattaya, who had been married for 20+ years to a Thai woman. He got real sick and had to return to the usa for hospitalization, his wife applied for a visa to go too, but was denied. He died alone. Not a big fan of the US embassy in bkk.
this is Thailand, guess you haven't learned that. You can bitch and moan all you want, I prefer another approach, and while I understand your complaint, and it's valid, I'll say it again... this is Thailand.
the airlines will often ask for proof of travel, because if they don't and you are refused entry, the airline can be liable for the cost. one time China air required me to sign a waiver, out of probably 12 one way trips... easy solution is to use the onward ticket deal, just before your departure. 10-15 bucks gets you a legit reservation, then it is canceled within 2-3 days.
I have gotten one by mail from AAA in the usa while living in Thailand. there's a branch in florida that offers this service, you send a copy of your license with their form, and 20 bucks, they mail to you in Thailand.