It's not because his feats are "solid" , it's because he doesn't have any PIS low showings that made the viewers like him. Even the other Spriggans have got good feats , it's that users here ignore them because of their low showings. Ignoring the context of the fight , ignoring their good feats.
I'll give a classic example. Brandish is lowballed saying , " Oh , she couldn't stop an enhanced Neinhart , whereas Natsu two shotted him , so she's fodder ! " completely ignoring the fact that Natsu's organs were being manipulated by her just two panels later. Completely ignoring the fact that magic power has got nothing to do with durability . Natsu would probably oneshot Brandish if he hit her with his attack , does that mean her MP is less than him ? No ! Durability has got nothing to do with magic power. Neinhart might've had shit durability to get two shotted by Natsu. Had Neinhart used his historias , Natsu would've been fucked since his historias would've been a lot more powerful than before. And multiple at a time.
Wendy and Erza are wanked saying their MP was matching that of Irene even when we have Wendy stating that her MP is nowhere near Irene , just because Erza's slash harmed Irene which has got nothing to do with magic power. Zeref is lowballed saying he struggled against base Natsu even when we have himself as well as Irene confirming he's playing around , and the fact that he oneshotted base Natsu at the end of the fight and forced him to go DF is ignored by everyone. Completely ignoring the fact he had enough power to easily enchant a frickin' dragon into a human , created a spell capable of oneshotting an entire army of 1 million soldiers , can stop time , can immobilize people and can do to them what he did to the book of END and what August did to Mira. Larcade is lowballed saying he lost to WSD Sting even when we've got his feats of flooring Gildarts and Laxus , completely ignoring the fact WSD Sting was immune to his spells. Serena is lowballed saying he got oneshotted by Acno completely ignoring the fact Acno was playing around while fighting the other 7 DS and wanted them alive , whereas he was serious while attacking Serena and Gildarts. Completely ignoring the fact that Serena stomped Jura and 3 other characters who were roughly equal to Tartaros Jellal.
I can go on , but this is what I wanted to say. That users here don't at all consider what impressive feats the Spriggans have shown , and only crop their low showings , which were completely situational. August doesn't have low showings , so he is not lowballed. Users don't like the other Spriggans , so they lowball the shit out of them.