For me it's more of a time thing. My preferred printing medium is ABS (because I like to stick stuff on my dashboard) and I don't want to have to wait for glass cutters and such to come in, then spend 20 minutes at the sander getting a nice finish on it.
Though now I have to wonder... if I sandblasted the glass bed would it give better or worse adhesion? I may have to get a couple pieces and blast one to see.
SD3 w/ RUMBA (8825s), merlin hot end (in pieces). Ender3 w/ silent board for PLA printing. Ender5 w/ silent board, e3d v6, new z lead screw, and glass bed. DiY Kossel w/ smoothieboard (in pieces). Vellman Vertex (in pieces)
Shapeoko2 router in process of being converted to laser engraver (in pieces)
Multicam 5000 series CNC Router w/ 11HP spindle, 5x10' table, and auto tool changer (in pieces)