A few random thoughts...
-It is almost never cool to publish someone's private correspondence without their permission. To do so implies a lack of integrity and trustworthiness, and particularly so in a case like this when you know the person passed up the opportunity to respond to you publicly, and specifically chose to do so privately. If you need to publicize a particular part of their message that you know without a doubt that they would be ok with, then do so by paraphrasing that general pertinent part. In this case "Danny has contacted me and for his own reasons has decided that he does not want to play at this time" would have been appropriate.
-Maybe Danny only wants to play a match like this when he feels he is at his very best and it is not just an excuse not to play. I can understand this line of thought for a couple of reasons, even when free money is being turned down. For starters, if you have a poor showing, it can hurt your chances for future opportunities. A poor showing can lessen how much of a draw you are which in turn hurts your chances with sponsors, future streaming opportunities, etc. Plus, the more you dislike a person, the less you want to play them when you are not at your best. It's one thing to get beat. It's quite another to get beat by someone you despise, particularly if you didn't even make it a good match. So maybe you would play that person when at your best, when you know you have a good chance to win and would at least certainly put up a good fight, but you would pass if you were off your game and might get blown out, even if you turned down some free money in the process.
-I can totally understand being upset that your opponent was offered more money to play in a previous match up, when you both were just as equally required for the thing to go off, and you were both close to the same level of draw.
-Sometimes pride makes us make really dumb decisions. The best decisions are always made with logic, and pride always lessens our use of logic. It may not necessarily be the smartest choice to pass up free money just because someone else was offered more than you for the same thing in the past, or just because you are afraid of not looking as good as you should, or any number of other reasons. Ultimately each person has to make this decision for themselves, but pride has caused us all to make many a decision we look back on and regret.
-It could not be put any better than Underclocked put it, but Danny has a mental illness or at least some type of issues that are beyond his full control. What often happens is that people will pick on them even more because of it, instead of doing what they should be doing, which is being much more understanding than what they would have been with the average person for the same thing.
-This offer from TAR is about as good as it gets. Smaller money that is still worth it if you lose, larger money that is even better if you win, free vacation to one of the most popular and premier destination cities in the world, zero expenses, experienced and unbiased reff'ing, controlled environment and rules that you have a say in, etc. The down sides for a player cannot possibly be minimized much more than this.
-One thousand dollars, when you don't have any costs, is not an "insulting" amount if you were to lose every set. Assuming that you fly in the day before, and fly out the day after, this is five days "work". That equates to $200 a day. Two hundred dollars a day equates to a $52,000 a year job assuming five day work weeks. Considering the state of pool and the amounts that can be earned in it, getting a minimum rate of pay that is equivalent to $52,000 a year is not insulting in the least. And that is just for showing up and losing everything. On top of that, you have the chance to earn even more. If you can win, you can make up to $1,000 a day ($5,000 total), which is the same rate of pay as someone making $260,000 a year (over a quarter million dollars!). Sorry, but I just don't see the insult.