You must have missed this part maybe, comparing total volume etc.
3-Second Tempo 7-Second Tempo
Load: 225 225
Total Reps: 8 4
Total TUT: 24 sec. 56 sec.
Volume: 1800 lbs. 900 lbs.
Peak Conc. Tension: High Low
So while the extended TUT set hurt a lot more and while it may have produced higher metabolic stress, the much lower training volume and peak concentric stress is a significant downside.
Then offering EDT as an alternative. No need for all the negativity imho.