Craig 99% of bunq's target group probably never needs anything else than SEPA bank transfers. Therefore I would reckon that there just isn't a huge need for further developing SWIFT transfers, which would be a costly thing to do. And most of the time, they work. I have received SWIFT transfers before. Not sure why your bank in particular has an issue here, but I'm also merely a user, not working at any bank :)
As for why I recommended Wise: I use them myself and they have a partnership with bunq, so therefore I consider them quite trustworthy in general.