Given that Rinnosuke does jack shit in canon besides run a shop and be snarky to the girls who frequent it, the only reason you could possibly find him horrible is if you're a yurifan that mad that Gensokyo isn't some Happy Male-Free Magical Anime Waifu Land.
Because seriously, he doesn't even do anything deserving of hate.
You could argue he is partially responsible for Marisa because he gave [and personalized] the Hakkero to her.
Which is probobly a large factor in her thefts and such. But also a factor in her being a protag... oh wait Reimu is canon in most games except MAYBE SA and UFO [Where it's one of the Sanae routes because Myouren actually forms]. Reimu is generaly canon unless canon directly contradicts it. [UFO]
So it's not that Rinnosuke hasn't done ANYTHING in canon. He's done things indirectly. You could argue everything Marisa has done from EoSD onwards is in part Rinnosuke's responsibility. Heck; if Marisa did not have the Hakkero; she wouldn't be in DDC since she had no weapon to act up. Rinnosuke is the reason Marisa can perform the Master Spark. Where would Marisa be without that?
Which; for a guy who's not even been in a game besides a background character in HM; is pretty darn impressive.
Anyway, I hate the 'No Males in Gensokyo' perception as well. I support 'No superpowered males' with the exception of Unzan/Tenma [Who is called a Lord so we assume is male; although Miko is a Prince and is female so -_[._.]_- ]. But no males? Hell no. Maybe there is a lack of male youkai. Maybe they were more aggressive than females and killed each other off. But male humans certainly exist.
I mean; we know of several males who exist in Touhou:
Marisa's father
Rinnosuke
Genji
Unzan
Yorihime/Toyohime's husbands [They are canonically married]
Youki
Likly Lord Tenma
Mokou's father
That's 9 males who have been mentioned or seen in Touhou, although 1 is posthumously [Mokou's father], but he's pretty much the core of Mokou's drive for revenge so he's kinda important. That's far from 'No males in Touhou'. And this is discounting the 'Maybes' like Sariel and characters who have not been
mentioned but obviously exist, like Maribel/Renko/Sanae's fathers. Even if we assume Youkai can reproduce without a male by magic Youkai stuff; all humans would still need both genders.
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Also I'm probobly guilty of one of the biggest wild mass guessings for Elly [To the point I give her a country of origin and even a date she must have existed before]. But at least I don't turn her into Yuuka's chew toy. I hate that. [I usually think Elly as the only one Yuuka treats with any modicum of respect because of her loyalty; the opposite to what many others think.]