Firstly, as with all forums, those who reply on a forum are often a select but vocal group of a much bigger playerbase.
Secondly, people are more likely to voice their complaints than voicing compliments. That is way companies lure you into writing a positive review with all kinds of tricks, companies know the negative commands are free.
Thirdly, statistically the players on this forum care more about what others think. Because those who care what others think are more online or on this the forum. Achievements are a good way to show off, showing off is best done online, so players on this forum are more likely to be attracted to harder games, not because they like it (hence the complaints when the games difficulty is increased).
I mean just type 'EU4' on Google and 'EU4 Cheats' is one of the first four results. EU4 is one of the most cheat friendly games out there. Yet the topic is hardly spoken about on this forum.