How would we restrict the tools? As long as Bitcoin is open-source, the blockchain storage format is openly available. As far as I see it, it would be wrong to try to block or outlaw tools for parsing the blockchain. People should be able to freely analyze its contents.
Yes I agree and I'm not in favor of restricting any tools, but by requiring tools not readily pre-installed on millions of computers you raise the bar for anyone wanting to trash the public's opinion of Bitcoin.
If you distribute encrypted copies of illegal content, the recipients are far less likely to get into troubles if they don't possess the key. The "key" in this context would be the tool that analyzes the blockchain.
/usr/bin/strings from binutils hardly qualifies as a "key" because everybody already has it.
If we have a problem with content in the blockchain, we need to either find a way to deal with it or learn to accept it. Hiding it won't make it go away.
True - I'm just arguing that changing the blockchain format is easy compared to Gavin et al. or bitcoin.org having to fend off the next DMCA takedown notice. By making the blockchain less attractive to distribute arbitrary data we can probably reduce that risk.