This doesn't really surprise me. I've noticed for a long time that an energy drink or other caffeine source hits different than a cup of coffee.
When I used to work late at a nursing home, I'd sometimes have a cup of decaf for a pick-me-up (that's all they had). Just the ritual and feeling that I was drinking coffee was enough to give me a small boost, even though logically it didn't make sense.
I never felt like caffeine did much for me. I would down a 2liter of mountain dew while studying in the evening and then go right to sleep back in college.
In short, if you want to feel not only alert but also ready for action, merely ingesting caffeine won’t cut it. You will need that full coffee experience.
Factors like coffee’s distinctive aroma and taste possibly drive this finding. Or the psychological expectations tied to the drink could play a role.
This article also essentially says the study was done kinda poorly and all conclusions that were drawn from it are not verifiable.