The money grubbing part is that the existing free version will expire and you will no longer be able to use it. So even if you are willing to use the existing product (which doesn't require a "dedicated team of developers"), you are out of luck.
Also, what stops people from saying "it's money grubbing to have a crippled freebie like this and demand $35 for full version".
$35 is nothing. I wrote decompilers and they're pretty damn hard and require constant upkeep and testing.