No, I think there are other things going on here, like why the mining address hasn't been released yet.  If FC wanted to release the address, it would've served as a prime advertisement for tube sales ("LOOK AT OUR AWESOME HARDWARE").  Since the blockchain is public, competitors in the mining space shouldn't care whether or not whatever isn't their hashing power comes from a single or multiple sources.  Ergo, while reluctance to reveal the mining address could be a factor of "Wait and see what we can do!" to couple dividends with those of tube sales, its more likely a "no news is bad news" scenario in this case, as though there's not much worth showcasing at this time.  And if every prototype, spare unit, defective-but-recoverable board isn't hashing toward revenue generation in the company mine, that's a serious problem in and of itself.

Its also obvious at this time that AM hasn't setup their own pool.  A public pool, for which AM already obviously has the servers from their last solo stint, could have been used to defer electric costs via a pool fee to undercut competitor pools and attract additional mining power.  Plus, instead of wasting time fiddle-dicking with the firmware/stratum proxy updates, the public pool could have been preconfigured to issue and accept tube shares at an optimal difficulty across the pool for both AM and its customers.

The lack of a concise marketing plan is also going to be a factor - you have a large part of tube sales going to non-Chinese-speaking countries, but very little support, marketing materials, or documentation in any language other than Chinese.

TL;DR: Shares are losing value because:

1 - missing promises (and none of this "he didn't promise" - in the business world, forward-looking statements by executives ARE promises)
2 - lack of standardized (let alone innovative) pool strategy, leaving customers nearly as screwed as with pre-orders
3 - its been said time and again, but website and marketing materials - anytime you're having to rely on grassroots efforts by shareholders...well, its not really capital you're holding as shares anymore then, is it?

That being said, the pricing of the tubes, even given the slight miss in performance, is absurdly phenomenal.  I'm not sure we'll see anything close with SHA256-based hardware at this price and scale for years, and possibly ever again, and certainly not after the next block reward cut.  For those that have BTC reserves from before the recent price drop, or who purchased before and are receiving refunds, the units are a steal objectively - once the proxy kinks get ironed out, sales should stay steady for a while to come.