I would not be too disappointed, often people get into beta testing for the wrong reasons. Sometimes they think that it just means playing around with something as you would with the regular sim, and the benefit is that you get to see stuff early, but of course it is not like that at all. It's tedious, repetitive and requires dedication, and is time consuming because of all that. Sometimes people will volunteer and then realise this with dismay, others will begin and their enthusiasm for the task will fall off. and some won't do as they offered.
I was recently offered the chance to join the beta for the Pirates of the Burning Sea RPG (twice actually), and regrettably had to turn it down, as I knew I would not have the time to give it what it deserved. Of course, when one applies for something like that, it is many months before the opportunity presents itself in actuality, and in the case of POTBS, I think I put in the request almost two years ago. As such, one can never be certain that the free time will be there when it comes to actually doing the testing.
All we can do is urge people to think carefully about volunteering for this kind of thing, as it is often not the bed of roses it appears to be. This happens with software reviewers too (of which I am one for Avsim). Ostensibly it looks like a great deal to be a reviewer - getting software for free and just knocking up a quick article about it - but the truth is one has to spend numerous hours researching stuff in order to write knowledgeably about matters, for to criticise something in error and wrongly affect people's opinion of a product would be unforgiveable! So in the case of reviewing aircraft and add-ons for flight sims (as I do), there are countless boring hours of repeating the same flight over and over again with different configurations and in different weather etc, etc, loading it into Vista, then XP, then FSX, then FS9, then on a laptop with a different graphics card etc, etc, not to mention poring over technical books and measuring the accuracy of 3D models and flight modeling. Frankly, if all I was interested in was getting the plane for free, it would be far less hassle simply to buy it and not have to do the review! But, since I like writing reviews, and think it offers a valuable service to do so, I indulge in this kind of thing.
So don't be too harsh on people if they lose enthusiasm for things JCWolf, in the end people appreciate your work, just not everyone is cut out for doing that sort of thing, if everyone was, the world would be a bit dull. and you can never be certain of someone's reason for not showing up, it may well be very reasonable.
Chock