I'll refer to "you" but this is not aimed at someone specifically:
filtering what your node will relay to others is not censorship. You're enforcing your right to run free software that does not diverge on the consensus level. And since Censorship happens only when someone succeeds in imposing their view on others, I don't think I would consider a client-level policy as a censorship activity. You'll get spam relayed to you through someone else or, eventually, through a mined block.
Also, if 99.999% nodes would run aggressive filters, then a spam non standard transaction could still go through via an off-band communication with a miner.
If you care so much about using the timechain for non monetary purposes, then at least take the burden of paying a lot more for the spammy transaction by contacting a miner. That's how filters work by the way, they increase the cost of spamming...and since the increase is only by a few Xes (3x, 4x or so) then I'd say that's even cheap spam.
And yes, not making bitcoin more private and fungible is an issue.