So if a Thai woman wants to come to the US to see New York City or the Grand Canyon they cannot? Yet I can just jump on a plane and go see them??
If she is young, single, has no permanent long-term employment, no significant financial assets or property ownership, then she will likely be denied.
U.S. policy dictates that a visitor visa applicant show substantial proof that he/she will return as required.
Unfortunately, a high percentage of visitor visa holders from certain countries never return home, but overstay in violation of our laws. For those countries with such high fraud rates, the chances of a woman as described above getting a visitor visa is extremely rare, but still possible.
Who is to blame for this policy? The lady's countrymen who went before her and didn't return. They screwed it up for the rest of their fellow citizens.
For certain other countries where the fraud rate is very low, it is relatively easy for almost anyone to obtain a visitor visa for the U.S.
For the price of only USD $100, she can file an application for a visitor visa and see what happens. Being denied does not preclude her from trying again later.