I agree....the bench press is not a core exercise. It's a chest exercise. If you want to work your core...just stick to Swiss ball exercises and keep your feet on the ground when benching. Lol
I don't think he meant "core" in that respect. Bench is a staple and has been for years. They don't call it one of the big 3 for nothing. Should it be? Geez, who really knows and who cares. It is a great exercise IMO.
It isn't about just training your pecs and it def is not just a "chest exercise". Training your golgi tendon and strengthening other tendons is a major part of training your CNS and body to be steady and manage itself under large loads. I won't guess at anybody's bench number but thinking bench press is a chest exercise is just plain false. You obviously work your chest, but there isn't a really good way to engage many of the other large muscle group with loads that will strain and strengthen your CNS long term.
I've read post from both of those guys and I agree with both sides of this.
If you are training to lift heavy, get strong, and grow then pulling your feet in the air or not incorporating driving your feet into the floor isn't the most efficient way to do this.
If you are honing your skills and working on a smaller portion of the exercise (whether that be for injury sake or just taking a lighter day), I'm not sure anybody could really make a case that lifting less weight leads to more growth and anybody that tries could be considered "stupid".
Lastly, if you are in there to knock out 21 sets a day and you don't care what the exercise is as long as you get your set done, maybe this practice is perfect for you. Albeit, IMO it will encourage you to remain lazy and fat, but that's just my opinion and I'm partially kidding.
With the advancement in machines and the wide variety of equipment available at most gyms, I'm almost certain there is an alternative to pulling your feet up. Then again, if there isn't, there isn't, who really cares. Lift heavy, use perfect form, eat clean, train like a warrior. These things will make notions like this seem irrelevant unless you are a power lifter of some sort or just one of those weird guys in the gym that does awful looking exercises to train a muscle via isolation when a heavy load for a compound movement would be more than sufficient. Might as well argue grip too (if an MMA guy pops in here, go ahead, eat this one up).
Morry