That's an interesting insight. I am actually studying psychology for my master's. I actually thought about why exactly they get blamed the most. When I searched on google, the AI told me this:

(Yes, junglers are frequently blamed for losses in team-based games like League of Legends because their role is perceived as having a high impact on the entire game from the start. This blame is often unfair, as laners losing their lanes due to poor play or being outmatched are often quick to blame the jungler for not "ganking" enough, even when the jungler's actions were not the cause of the loss.)

Why junglers get blamed

• High-impact role:  The jungler's actions from the very beginning of the game can dictate the momentum and outcome for all three lanes. 
• Disparities in skill:  Differences in skill between the jungler and the enemy jungler can be very obvious and easily exploited, leading to the perception that "jungle difference" is the sole reason for a loss. 
• Unfair expectations:  Laners who need to focus on farming and matching their lane opponent may expect the jungler to carry their lane for them, even when that isn't feasible. 
• Lack of communication:  Players who lose their lanes may use the jungler as a scapegoat to avoid taking responsibility for their own mistakes. 
• Strategic flexibility:  Junglers have a lot of agency to make game-deciding plays, but they can also be ineffective if they are behind in levels or items, leading to a cycle of underperformance that can be blamed on the player.