IDK why this dev is getting such negative feedback...
sure, things need to be polished here and there. some of the features are rather disappointing and can be seen as too much ambition for a one-man dev indeed. If that's the case and you want the game to flourish with the content you desire, you should give proper feedback about what seems to be causing the problem and what would be the possible solution.
If the players' attitude is like 'this game sucks IDFK why I should play this shit', then the players should simply quit playing the game because it will make both players and dev unhappy and will do absolutely nothing productive... especially such games in early development. If dev doesn't care what the majority of players suggest without very good reason, that's another story tho.
That being said, I would suggest dev should focus on the framework and bug fixes rather than any extra content at this stage of the game. any extra content will be useless or simply cause rather unpleasant experiences for players.
Also, giving up some features of the game is considerable. For example, if the pregnancy feature is full of buggy mess and if it seems to do no good, why keep it while getting all the negative criticisms? If building feature is causing too much of development resource starvation, dev should consider giving up such feature because... it could be fun in the end, but nobody is getting aroused while building their own wooden house.
ah, yes, "if the players dont like it they can simply stop playing and not say anything at all". how i love this argument. you see, this argument is literally pointless, it's worthless pandering to people with sensitive feelings. you literally answered your own question in the first two sentences; why does the dev get hate? well, isn't it obvious? you listed a lot of the minor issues people are having with the game, let alone the major ones that have been mentioned on here.
tell me; how is a video game dev supposed to know what players are finding wrong with their game? how will they improve if they dont have anyone to tell them what's wrong in the first place? sure, they're a dev, but they can't do everything, and sometimes only some players will encounter a bug while others won't. it goes like that, really. players want their voices to be heard, and want devs of games they see with potential to improve. sure, they could be nicer about it - but the tone-deaf "i dont know why players are saying the game sucks" after pointing out many reasons why the game sucks is just *chef's kiss*.
look; you don't want a dev getting hate. that's ok. but when the game is slated for a full, fully-priced release that people will have to pay money for - on other platforms at least - and there are game-breaking issues that dont seem to be getting solved? then yeah, players are gonna be pissed and angry because it doesn't feel like they're being listened to and, therefore, like the dev doesn't really care.
also, people are scared of another Breeders of The Nephylem dilemma - the dev casually ignored players and their desires, actively does whatever they want, burn themselves out with 'no ideas', and then complain when they get backlash after not updating the game for literally over a year now. and they, too, were planning to seel it for a full release.
THAT'S why players are being harsh and complaining.