There is no setting to turn this off, but you can disable this by deleting the Site.Mobile.Master and ViewSwitcher files
The following files are no longer needed:
Site.Mobile.Master
- Site.Mobile.Master.cs
- Site.Mobile.Master.designer.cs
ViewSwitcher
- ViewSwitcher.cs
- ViewSwitcher.ascx.cs
Thanks to @fortboise for simplifying my answer
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…