they are for hobbyists, they are not industrial machines but they can do just about anything the industrial machines do just slower.. My Shapeoko 2 is a hobby cnc and I cut ACM, PVC, Foam, all the time cuts nice and with precision.. They are a great way to "Learn" the mechanics and software before going into industrial machines.
I am expanding my shapeoko to 5 x 8 as we speak and will work great for the aforementioned substrates as well as acrylics for engraving, FCO and the like.. I will attach a drag knife to be able to cut like that as well.. Like I said a great way to get into it without spending a fortune then learning how to do it.