You fundamentally misunderstand JDT's brief.
He has been given the job to manufacture saleable assets and avoid relegation, not necessarily to win football matches. It is clear he has little say in transfers, responsibility there appears to lie with the director of football who appears to be in a similar position in that the club has directed him to reduce the wage budget as far as possible and maintain a playing staff that can be sold for profit.
The "style" is a direct result of this as Premier League clubs want to be paying for technically proficient prospects rather than seasoned championship battlers.
Perhaps this is a reaction to the money hemorrhaged on Rothwell, Brereton-Díaz, Lenihan - even Dack. Perhaps it's necessitated by Venkys financial position. Perhaps it's both. But it's clear that the thinking at the club currently is that promotion is too unlikely to bet the farm, and so this is the model for long term sustainability.
I'm not convinced it is going to work (and certainly doesn't seem to be working currently) but it seems pretty clear JDT is working with a player development focus rather than a "win at all costs" mentality.