And now the GMail storage limit for free users is 15 GB, 15x what it launched with. I think it's rather naïve to expect that any free service will give you unlimited space or unlimited time. A 2-year inactivity period sounds reasonable to me. Literally all you need to do is log in once in 2 years to not have your account deleted. I often disagree with Google's handling of things, but this isn't one such instance.
And set up Google Inactive Account Manager* so that in case you unexpectedly pass away, somebody you trust gets access to your account after a set period. I've set mine to 3 months because I'm online so much, but you may find 6 or 12 months to work better for you.