No... why be peeved? Because they are a company doing what they are supposed to do by constantly evolving and making better products?
Would you rather that WebAssist stop making a particular extension better every time someone buys one?
I am sorry, but that makes no sense at all. You still are getting the very product you purchased... it's not as if they are taking away your license for what you did pay for.
I also think this is exactly why they started the subscription service because then if you subscribe, you'll always get the latest product no matter what.
You buy a product because it can help you get a job done. I think that is still the case with the product you purchased. It's not much different than a couple years back when I purchased my iMac only to have Apple, a week later, introduce the new iMac with Leopard and new software. Should I hate Apple for evolving and releasing a better product line each year.
Try to look at it more positively... the good news is that WebAssist continues to innovate on behalf of its users' needs.