No one is forced to pay for Beta access and Frontier has put it on record that the pricing structure was set to discourage casual gamers from entering the beta process.
This is first time I hear that one gaming company wants to discourage casual gamers by setting the pricing structure. This doesn't make sense to me. Well... how it goes? You learn something new each day.
Anyway. What makes you think that only "pro gamers" are purchasing beta? In my experience, beta tests -be it payed or free- are, from the player's perspective, widely seen as mere preview of the upcoming new content and chance to carelessly play around with it. Just a small fraction of beta testers actually bother with bug reporting. It's a fact.
And then, as the casuals make up for majority of playerbase (as usual with all games, except perhaps hard core sims and grand strategies), what you get at the end is live version in which,
just as an example (sic!), NPCs are too tough for average player. Followed by outrage on the forums, drama, hotfixes and generally a mess which probably costs them more than they might have made by selling beta access. I really can't see why more beta testers is bad thing, and I also don't believe that FDEV is actually making a lot of money by selling beta access.
After all, this should not be about money, but rather the quality of testing process; which, in my opinion, lacks quite a lot with ED: we all know that the patches, more often than not, are being regularily pushed out full of bugs and imbalances which then sometimes stay in game for months (or forever).