That's what I've heard, and it makes sense. The plastic lens from the factory, when new, is at it's most perfect, non-porous state. Opening up the surface with sandpaper, buffing compounds, etc. does seem like it would make the surface degrade faster over time.

But, when the lenses are as degraded as mine were, there is little choice besides full replacement. I'm going to find a UV sealant in the next few days, apply it, and hope for the best. If I do end up performing some maintenance to them in a year or so, I imagine I'll be able to skip the more abrasive steps in the restoration process and just do a light polishing compound.