Even if you make the case "getting it", how do you have a serious online racing game with out Spa and Le Sarthe or more to the point just a lack of real world tracks. In a few years time or GT Sport 3 it might be worthy of a good score.
As a GT fan of old and in the context of pre Sport I remember the excitement on gtplanet when Spa finally came to GT. It was a long decade awaited track that arrived via DLC in GT5. 4 years into PS4 and about 7 seven years since GT5 there's no sign of it.
Quality control is one thing but GT fans would like a meaty HD GT game within their lifetime. When PS5 rolls around are we going to be back to square one again, 80 cars a handful of interesting tracks.
When the PS2 era ended I would've thought PD would be up to speed with 500-600 cars, all the classic courses updated plus new tracks 10 years into the HD era but here we are with GT Sport. With the money made from GT, if you can't get the content ready in the HD era then you need to employ more or find people to outsource to, PD aren't the only ones who can model cars. They could've overseen a quality outsourced group if they started in 2006 or 2010 and be ready for PS4/PS5. I can see PS6 being Suzuka and one car, have to maintain the quality. It takes a team of 10 6 months to model a wiper arm don't you know, you can't rush it. Perhaps science will make us immortal and we can experience an updated GT.