Some of the confusion is arising because people do not understand as to what is meant by intentional doping violation.
Maria did not claim that she opened her mouth and Meldonium tablets fell from the sky and then it immediately it started raining pushing it into her mouth. She did not claim that someone spiked her drink with Meldonium in powedered form and thus she accidentally ingested. She has admitted taking the drug intentionally. In fact, she has admitted popping one before each match at AO.
The trouble is taking the drug intentionally is not the same as intentionally violating doping laws. She claims that she is not aware that Meldonium has been banned, which is possible. Assuming her claim is true, she is not guilty of intentionally violating doping laws.
Now, you may say is not she responsible for knowing that it has been banned. Yes, she is responsible for knowing that. That is why she is being given a ban of two years. She is not allowed to go scot-free due to her not knowing that it is not banned.
Two important issues are who has the burden of proof and what is the standard of proof employed here. If the substance is a "specified substance", it is the burder of ITF to establish that the player violated doping laws intentionally. If the substance is not a "specified substance", it is the burden of the player to establish that they violated the doping laws unintentionally. Meldonium is a specified substance and so the burden of proof fell on ITF to establish that she violated the doping laws intentionally. Now, you can understand that it will be hard to do so.
Finally, there is an asymmetry in the standard of proof employed also. Whenever, ITF has to prove something, the standard employed is "clear and convincing evidence" (this falls in between "mere preponderance of evidence" and "beyond reasonable doubt" standards). On the other hand, whenever the player has to prove something the standard employed is "mere preponderance of evidence" (this means it is more likely that whatever player is saying happened as opposed to the other possibility).
So, not only that the burden of proof to establish that Maria violated the doping regulations intentionally fell on ITF, they were expected to establish that in a clear and convincing manner. That I suppose would be very difficult here.
Actually, while we all justifiably think Maria is a cheater (as she was popping pills for performance enchancement for about 10 years), we must admit the possibility that she might not have continued to pop these pills if she knew it were against doping laws (perhaps not because she cares about being legal as a virtue, at least because she would be concerned about the consequences).
Hope that explains the issues involved.
So, I think the decision of the tribunal was fair.
p.s. Some of this post is wrong. See next post.