Hmm, I've had the complete opposite experience. Swiftkey's beta program has been great to me. Either because I purchased Swiftkey 2.x or because I also signed up as a VIP to receive Swiftkey 3 beta (from awhile ago), I receive updates and emails about their betas usually the day of or day after blogs publicize them. Seems great to me, especially since they include the direct apk in each email. I don't see the issue here.
You sound unnecessarily riled though, they gave you a $2 discount off a $4 app for beta testing it. Additionally, Swiftkey frequently has a sale on their tablet and phone app even outside of holidays. Swype, before they included OTA updates, had a measurably worse practice. The only way you knew about newer betas was because your version stopped abruptly when you typed and you had to log into their site to download a newer beta. There was no supporting email system like what Swiftkey has.
Edit: I just checked and Swiftkey is $2
right now. Hasn't it been on sale since Swiftkey Flow was officially included?