Namecoin: is there any rationale behind the (apparently foolish) choice of having the domains cost an irrelevant price? When I first heard of namecoin an address costed 50 NMC, now they are priced 0.01 NMC.

This means they are as much as free, and the only thing preventing someone from just brute-force registering tons of them is... that it is pointless to do so, because due to this problem itself, namecoin is essentially a worthless project.

Using a bitcoin-like currency to handle DNS was a nice idea at first, and I have no clue about what could have caused them to mishandle the design so much.

Question is, did they state somewhere the reasons behind this apparently foolish decision to set the registration prices to "basically free" after a little while? Didn't anyone point out how stupid that idea was?
When I first looked into this issue the low price for name operations struck me odd, too. But the rationale behind it is to allow to register as many names for as low a price possible. You need to realize namecoin is not only about domains and the dot-bit project is only the first large namecoin project. namecoin is a generic name/value accounting system. 
Still, because dot-bit was the first project based on namecoin the design had an initially high price for registering names to prevent squatting. Actually it worked very well, if it had not been there I and others would have registered thousands of domains much earlier.

there was a discussion about fees and thoughts about modifications here: http://dot-bit.org/forum/viewtopic.php?f=2&amp;t=360

By now almost a 60000 domains have been registered so imho it is more important to have low name prices to allow other usage of the namecoin system than to further prevent squatting: possible use cases