As mentioned above - the Roadracers are designed to fail safe.
I remember seeing a report in Cycling Weekly a few years back about a cyclist who had been very seriously injured when an acorn (of all things) had jammed under his front mudguard and sent him over his handlebars.
I'd rather have mudguards that shatter when debris gets under them, than risk something like that happening. It's bad luck when it happens so do your best to avoid running over stuff to minimise the likelihood of it happeneing.
As many CycleChatters know, I promote Crud Roadracers (see signature link for review!

) and am a fan of the design. In all fairness though, I have broken mine twice - once when I got the strap of my Camelbak bag caught in the front one (I absent-mindedly yanked the strap rather than untangling it), and once when I dropped the bike on the rear one when trying to get through an awkward gate. I consider both of those failures to be my fault rather than a design fault.
The other thing that some people complain about is rubbing noises from the Cruds. Think about it - you are only using them because your bike doesn't have adequate clearance for conventional mudguards - of course there isn't going to be much room so things will get stuck in there from time to time! I don't like the noises either, but minimise them by adjusting the Cruds and riding through puddles to sluice out any accumulated Crud. It's better than getting muck all over you and your bike!
I'm not sure, but if you have the bits of the mudguard and send them back to the manufacturers they will replace the mudguard. I know they did replacements for the original crudcatcher.
As youngoldbloke points out - they now make a charge for that. (I reckon people were putting together complete mudguard sets by sending in for the various free replacements parts!

)