Java was released in 1996. It got generics in 2004, 8 years later. I don't remember anyone panicking and yelling from every corner that the world is ending. Everyone understood the benefits and it was a much awaited feature. And yes, after Java got them, it became easier and more typesafe to use. End of story. And by the way, Java too was a very simple language and generics didn't ruin it.
I never liked generics in Java - or basically the stuff they added together with them, like annotations and autoboxing - i felt they complicated and "ruined" the original language which was conceptually very simple. But by the time Java 5 became mainstream (i was working on desktop software so i had to keep compatibility with older runtimes anyway - not that i minded at all) i had already moved off Java aside from some of minor projects of my own (but i dropped even those after Oracle's acquisition of Sun as i didn't feel like relying on it). I do remember getting annoyed with NetBeans and Eclipse "helpfully" adding little squiggles everywhere in my code about how i could "improve" it with ranged fors, replacing typecasts in container usage with generics and adding those ugly @override annotations (which i manually removed whenever NetBeans added them on its own when it was creating code via the GUI editor). I guess i could disable them but as i wrote, i moved on after that anyway.
Of course i never panicked or yelled about it nor really even bothered mentioning it (aside from on HN now and then, usually in Go posts since the whole "generics in go" remind me of that time :-P). But me not doing that doesn't mean i didn't think of it and i'm guessing others did too.
My guess is that nowadays you see more complaints about generics in Go because Go largely attracted a higher percentage of people who liked its simplicity than Java ever had (and more people in absolute numbers in general as i'd bet that there are way more programmers nowadays than in late 90s/early 2000s, so you're bound to hear more voices). After all in terms of features as a language Go didn't had anything to offer over Java whereas Java had a lot to offer back in the late 90s/early 2000s.
(amusingly the language i use most nowadays is Free Pascal which is a hodgepodge of arbitrary features and a far cry from the original Java simplicity - though i do often find annoying how much of a "mess" it is)