Sure, $0.001 is the value on paper (and under current law). The point is, it's exploitable (let's say I'm an Apple engineer, I start a new company and get a wink wink from some friends in high places who want to invest in my company doing X. I put in my founders stock into IRA in return for first dibs on placement for the investor - 1 year later company has valuation, my stock has risen many %%. Sure, I'm technically doing everything legally, but practically it's somewhat equivalent to insider trading + avoids taxes).

I would personally ban non-public investments in Roth IRAs. That way a debate about market value doesn't have to happen.