The fight game has evolved. Lidell had nearly a 100% TDD. He is one of my favs of all time, but he struggled once taken down. Just take a look at the current roster of Champions on the UFC/Bellator roster. It's compiled mostly of wrestlers and submission artist. Straight boxing isn't being taught to MMA guys, Muay Thai is. The average boxer, even human, cannot take the punishment of a leg kick. I've seen fights stopped from them, and I have amassed over 2000+ fights in a 10 year span, not 30. Back on the local level we go again, a 51-2 Boxer fought for the first time in MMA this weekend. He lost in 52 seconds of the first Round. Who did he fight? An IKF World Champion Kickboxer, who happens to wrestle and do BJJ as well. Dude had no chance once he got the takedown, and tapped out to punches a few seconds later. I'm not hating on boxing, I love it, but it's so easy to see what forms of fighting are better to have in your arsenal for an MMA fighter. Take Holly Holm even for an example, her striking is elite, but you can guarantee she works more on TDD and her ground game way more now than her stand up. Stephen Thompson is another example. Probably has some of the best stand up in all of MMA, but his ground game has evolved tremendously in every fight since making it to the UFC, and it has gotten him into the Top 10 and a run at the Top 5...
Almost everyone I know has been hit with a punch before. Very few have had to defend an armbar or sub attempt. I'll take the punch to the face over a broken arm, any day...