I think you're getting confused with terminology. In JasperReports Server, it's create a Domain and then Adhoc View. Adhoc Views are interactive reports. An user may opt to generate Adhoc Report from an Adhoc View but this isn't really necessary.
An user may also opt to create a Report using Jaspersoft Studio - this does't require creation of an Adhoc View.
I think what's you're describing as a "view" is a "Domain" in JasperReports Server terminology. Data abstraction and security is a good thing and it's another few checks on features comparision list, but I've found most users do this in their backend application, database, esb, etc. rather than on BI server.
I agree with your audience's stance. That's why I've developed an addition to enable users to just drag & drop files on to a web page to generate Adhoc Views directly from the file.
The main benefit of JasperReports is very good reporting compared with other tools. Jaspersoft Studio is a very good reporting tool. Another benefit of JasperReports is that's it's open source - it's possible to customize it to suit each user's needs. With proprietary product, you have to take what they offer you.