^^ not true. A DA with a good cut pad and some compound will take them out. if they are deeper than that, which most aren't, then a wetsand and buff will get rid of them. The only time you really need to sand and repaint is when you have scratches, chips, etc that have taken basecoat off. And even then you could touch it up first.
I had water spots all over my car when i bought it. and they had been there for years. 6-8 hours with a PC later, and they are gone now.
2003 Azure Blue Mach 1 - KB, Suspension, Bolt-ons.