This relates to the show because Luke does the same thing in the ST that Kenobi and Yoda do between the PT and OT.

The difference is that Obi-Wan and Yoda were actively being hunted by the ruling galactic government. They had no choice but to stay hidden and bide their time. Meanwhile, Luke had plenty of better choices he could have made in that moment.

And his quest led him to the conclusion that he had followed the Republic era Jedi in a failed method of training.

That’s precisely the problem. Why did Luke stick to the failed old methods of Jedi training? He had no reason to do that, and given his unusual life experiences as a Jedi and his strong connections to his friends, he would know better than to just recreate the old Jedi Order with all its old flaws. It’s out of character, and only serves to brush aside Luke’s Jedi Order as unimportant for the sake of propping up the ST’s soft reboot of the franchise.

Also, look at Anakin.

Anakin’s sudden switch to hating all the Jedi and murdering them all is one of the most criticized aspects of the prequels. Though at least that had some sort of context for his sudden turn. The ST just did a worse, even more rushed version of that.