They can not have spent 18 months on this, this looks like a 30 or 45 day rushed amateur app. If it took 18 months to produce this garbage then they need a new coding team.
It is a 45 day rushed amateur app... but I've seen better ones out there!
I bet they spent all this time producing a better track creator but decided to save it for GT7 instead, especially if they're planning on announcing GT7 next year.
Technically, PD created a track editor for GT6 (albeit a very limited one), so they kept their promise... although it's far from what was expecting: it's only slightly better than GT5's track editor in some aspects and worse on others, namely accessibility to the app!