Personally, they had lost my goodwill already with their old upgrade policy. If you bought a license on 01/2014, it expired on 12/2014, and you didn't need the product again until 04/2015, the upgrade you purchase in April begins on 01/2015, retroactively beginning after the end of the previous license. So you don't get the full 12 months they charge you for. When I realized that it was the end of my support for them…
Why would it work another way? You are paying to extend your old license, of course it carries on from when it finished. If you want a year from the present moment, that's not an extension, it's a new purchase. Otherwise, no one would extend until after a new release came out once it ended.
Because I shouldn't have to retroactively pay for a period I didn't use a product and the natural thing for me to assume was my status as a previous customer/license holder was what enabled me to an upgrade with the advertised "year's" worth of upgrades? Because that's how upgrade licenses work for other software products? (Windows/Office, other stuff I've used.)
They can define a license however they want, it's just up to me whether I find it worthwhile, and I didn't.
But at least in those days I had the option of continuing to use the older version after it expired.