I think i know what he's getting at.
An example:
Stock A is an extremely stable company that makes no losses, and also makes no gains ( i know no one would invest in it but it provides an example). It could be something like bottled water, which has a constant value at all times. Anyway we agree this value *never* changes, its completely constant.
BTCs however rise in value, so if you buy Stock A then its initial value in BTCs is say, 100. But as time progresses its BTC cost goes down, not because the company loses, we agree its perfectly constant, but BTC value goes up. So with enough time that company will be worth 50 BTCs..... but its *value* is still the same. It's the BTCs that have changed. So why bother investing in a company when you can just keep the BTCs? The company is a great inflation hedge, but a terrible deflation hedge.
Now lets take Stock B, Company B is a mildly profitable. But its profits do not outstrip the deflation of BTCS. So if you own 100 BTCs of Stock B, then after the same time as above, instead of being worth 50BTCs its worth 75BTCs. Its still profitable, the value *has* gone up because it is higher than constant value company A, but its still only 75BTCs. Once again... why bother investing in it when you could have just kept 100BTCs?
The only way for this to work is for Stock C, Company C is INSANELY profitable. They exclusively produce an antiaging serum and charge insane prices for it. Their stock actually goes up because profits outstrip deflation, 100 BTCs worth becomes 150 BTCs after the allotted time.
So, to answer the original poster... BTC based stocks have to outstrip the deflation rate in order for those stocks to be worthwhile. Store of value stocks, like Stock A, or mildly profitable stocks, like Stock B, are not worthwhile investments in a deflationary currency scenario. Both stocks however are worthwhile in an inflationary currency scenario.
If however BTCs become very stable, then the deflation rate might be low enough that its relatively easy to outrun deflation. I'm not sure if this will happen with bitcoin in particular though.