Tired upgrading under payment.

I bought two full licenses of Parallels 9 very excited for two macs (personal and work). I thought how good it would be to use two platforms on the same computer.
Shortly (3 months only) came the 10 update and the system informed me of the upgrade option, paying of course. I kept running with version 9 as it seemed to work fine.
It was not long and update 11 arrived. Again, as was I supposed, have to pay for this upgrade. I was not ready because the short time I had my full version.
Now comes the FREE update of MAC OS sierra, and my PAYED version of Parallels no longer works.
Of course, I can not upgrade now, and I have to buy the full version again.
The decisions that your company makes seem to me to be detrimental to medium-sized clients like me, who will opt for other virtualization platforms that work very well and are free. I agree to pay the work of your high cualified programmers, but I think you are not aware that there are too many updates WITH PAYMENT. And what I think is worse, the program in short time will stop working: that's what I call programmed obsolescence.
I have to pay 49 euro every 6 months for each of the licenses if I want to upgrade (98 euro) or every two years almost 200 euro ? There are quite cheaper office packages ...
I am very disappointed with your product. I wanted you to know.