You have that kind of backwards. People are complaining this time because everybody has tried the 2015 MacBook and everybody knows exactly how bad those butterfly keyboards are.

When the 2015 MacBook came out, nobody knew what a butterfly keyboard was. Nobody had ever tried, felt, or melded with that keyboard. But journalists who got to try it did start hating on it right after the event finished.

Also, the MacBook was an addition to the existing Air + Pro product lines so you could just happily ignore its existence if you didn't like it.