Why do so many people dislike Windows phone? What's wrong with it?

I used lumia 520 for 2 years. After that I bought moto g3.
Why I feel many people will not like windows phone is

• Many apps are not there or updates are given after long time like quora, no Google apps, WhatsApp still many features are missing.
• UI is not good as Android phone's.
• Many of them will face hard time in understanding how to use wp.
• Compared to Android and ios these phones are less popular(india).

Though i liked many features like here drive, Microsoft products, very good screen, speed I feel above points are the reason for less shown interest on wp.