That was another thing about Sinnoh I disliked. Like you said, it didn't feel natural and lacked variety in most of their towns/cities. I was extremely disappointed that half the region wasn't covered in snow and that there should have been more ice pokemon to reflect that since one of Platinum's selling points was about about how much colder the region was. Being known as the "winter region" would have really helped it stand out on its own when compared to Kanto's "Basic region", Johto's "Modern-Fuedal region", Hoenn's "Summer-Tropical region", and Unova's "Futuristic region".
I also hated having to back track so much(this was the only region where I really need Fly). I also forgot to mention how that other than Cyrus and Cynthia's battle music and the Legendary battle music; Sinnoh has the worst music. I had to play on mute 90% of the time.