Oh yeah, those wire cups and wire wheels... I just means that lose wire that comes out of the wire wheel is going fast.
I bought a big Makita angle grinder - this one I think
https://www.makita.co.nz/products/model/GA9040S01 and it's great with cut off disks because they are thicker and less flexible. I don't think I've had a cut off disk fly to bits with this one. I thought I'd only use the big grinder one or twice (bought it to cut concrete) but I use it all the time. I also think it's weight makes it less likely to jump off the work piece and get you