Science is not about beliefs!!
This type of approximate security works for Monero, not for Zcash. It’s certainly your right, but I don’t like that you are making it sound like your suggestion of running personal lightwallet nodes is a minor issue. It is not:
We should use our time and financial resources to build methods that are improving the network, improving the privacy of our users. Weakening it is just plain bad, unless you have conflicting interests in this story.