more than a few in the MMA community seem to be doing the same thing they accuse TMAs of doing, namely not having an open mind and adapting things from other styles. The big complaint about TMA's is/was that they are insular, that they look to improve based on what is already "in the system." The same thing has not been uncommon with many an MMA coach for a bit now. Where MMA used to be about looking for the techniques that work across the multitude of Martial Arts, now there is a tendency to look at what you have and simply refine or create a new variation based on what already exists. The same thing that was/is the criticism of many a TMA.
Have you actually spent a significant amount of time with any successful MMA coaches? Because your generalisations here don't fit my experience at all.
I am acquainted reasonably well with four successful MMA coaches, two of whom are UFC veterans. I see and train with one of them several times a week, and work out with his MMA fighters.
These guys are CONTINUALLY seeking out new material, technique, training protocols, equipment. And continually going to or bringing in other coaches. My BJJ coach, who runs the oldest MMA gym in Sydney, has had visiting US wrestlers, a Judo 6th Dan, boxers, kickboxers, combatives teachers, etc. etc, teaching their stuff at the gym for periods of months. He's spent time with my WC instructor, who was also his BJJ student for quite a while. He's continually going to seminars and having visitors in to help tweak his game and widen his perspective on multiple fronts..
I am acquainted with a couple of 5th degree black belts, one of whom was also Royce Gracie's S&C coach for the early UFCs. Both are travelling extensively looking for people to help improve their skills in particular areas. One just spent a period in the US upgrading his leglock game to world class. The other goes to places like Mongolia and Russia seeking wrestling and conditioning knowledge, despite being one of the longest running and best known fight conditioning coaches on the planet.
One of my training buds won an MMA title with a gogoplata (as an avid observer of MMA, you'll know what that is). Another female fighter from my gym is on her second trip to JacksonWink - they have equipment and innovative training protocols that most TMA guys have not even heard of. She has a pretty sweet spinning hook kick to the head in her arsenal as well.
Do you really think coaches like Firas Zahabi, John Danaher, and Jackson / Winklejohn are sticking to what they know? They are innovators, very good at what they do, and go to MMA because smart people go where the money is. Jiu Jitsu, which is a major part of MMA, is continually evolving, inside multiple rule sets. The evolution of TMAs and their training methods have moved with glacial slowness in comparison.
Most good MMA coaches are too busy learning and innovating to bother criticising TMA's. Time is limited and they do not wish to waste it on unproductive pursuits. I suggest you follow their example and not worry about what people outside your selected domain might be doing, or saying.