I won't joke, some romhack and fanmade pokegames like Uranium or Flux (from the same devs) actually has a higher difficulty curve than this one. Your comment about people whining about the game being 'too hard' is spot-on, but for different reasons.
1: People are expecting a massively gutted pokemusu game with sex as focus. This game is the total opposite of that: a pokemon game first with added sex as bonus.
2: As point #1 says, people are expecting this is eroge first and pokemon game later. The people who didn't have the experience of playing the first 2 gens of pokemon or haven't played any fangames beforehand expects to get 'babied' with the usual 'rival took the weaker pokemon' trope. In a way, it's true, but with the inflated base stats those starters have stat modifier moves takes importance in the first battle. As for the scripted fights, I can't really defend Sintax because I did lose several times before the stars aligned and one of the opponent missed not once, but twice with their moves. It's one of those 'you need to load your save after researching about your opponent' kind of fight, which is quite unfair.