Where are you getting 1500 Soyuz flights? As far as I can find the number is more like 150. It also experienced failure and loss of crew on two missions (Soyuz 1, Soyuz 11).
It's correct. I have confused Soyuz launcher with Soyuz spacecraft like newbie. It's true. Soyuz spacecraft has early failures (till 1971, none after). Shuttle has late failures (2003, then project decommission). I suppose design improvement in Soyuz, engineering quality decrease in Shuttle. Incompetent early Soyuz design team. Incompetent late Shuttle engineering team. Lack of ethics to make such broken devices.