I participated and unlocked all the beach event rewards from 2015 last year. I've been able to thankfully cap every day on this beach event this year and so far have been able to complete mostly everything this year to unlock the 2016 rewards. With that said, I do think the stuff from 2015 should be realistically accessible to everyone. The rewards are purely cosmetic, and as someone who has unlocked everything, I don't see the point of restricting people from it. Its just silly cosmetic overrides and titles. It also doesn't make sense to have such a high requirement this year when the beach is only 4 weeks this year. If I recall correctly, last year it was like two months or so long as you stated. Seems a bit silly to have to cap 100 times for full rewards with only a few days max to miss out on before you're locked out of the rewards. I'm able to play a lot of hours, but most people are not. That shouldn't restrict them from cosmetics and titles that are meant to be for fun, not some sense of achievement.

tl;dr Make getting the 2015 stuff reasonable