I think that some balance needs to brought here. EasyJet is now a massive company with about 1200 pilots and about 105 aircraft (the exact numbers vary almost daily). A pilot's view of the company is understandably almost entirely dependant on which base he/she operates from. From my own perspective at Gatwick, we work hard but are by and large happy with our lot. Yes, there are a few of the FOs who are trying to get to BA, Virgin etc but that is a long-haul type choice. From my own perspective, I think easyJet is a good company to work for. It is not perfect and there are battles to be won and that includes not giving away the loyalty bonus for a few bob now with no thought to the future.
Regarding mass membership of BALPA, the overwhelming reason why there is not a higher membership is simply the 1% cost. It is too high and until they resolve that, we will remain with the level of membership we do. I am ex-BALPA but, despite significant reservations mainly related to wastage of money on foolish cases, would rejoin if it was cheaper. No doubt others will disagree but the fact remains that if the cost was less then people would join.