It's likely no one except for the Clippers right would would be interested in Harden.
This from a source but:
Harden's mother has been having health problems. The Harden to Houston rumors came up after visiting her, as she still lives in Houston.
The "no one wants James Harden" discussion is really because unless the 76ers were going to max him out, he wanted to go to either Houston or LA (where he's from originally and would move his mother and still will move her there if he is traded to the Clippers).
That's also why there is "only" one team he would go to. Free agency was really always Houston or nothing since he he still wanted to get paid. He was willing to accept less than a max for Houston but it's rumored he wanted more years. This would have still facilitated Houston getting Brooks and Brook. Udoka wanted to go in a different direction, specifically that he trusted FVV to be in a mentorship role while he expected Harden to be distracted not by clubs but by the health of his mother.
Harden still could have gone to the Clippers for about what Westbrook got, but he did want more money than that.
Harden's ideal choice after he got word Houston was going with FVV was hopes that Morey would facilitate a sign and trade to the Clippers. But because Morey wouldn't talk with Harden about that prior to free agency and after the Houston deal feel through, Harden opted in. Allegedly Morey had promised Harden he would work to facilitate such a sign and trade to the Clippers during the last season if they couldn't come to an agreement for a max with the 76ers or Harden's mother's health worsened.
If you listened to Austin Rivers' show a couple weeks ago, he was asked about the possibility of Harden playing for Team USA in the Olympics in part because they need good players and to help his image. Austin Rivers quickly dismissed that and said Harden has personal stuff going on and can't do it. Austin said this because he didn't want to mention the health of Harden's mother specifically but knows about the situation. While Harden did spend a few days in China, it's a lot different than spending an entire off season in France instead of visiting his mother plus there is the possibility he would have to leave in the middle of the Olympics. There just wasn't a guarantee he could commit the whole summer.