Its probably been 15 years since I've consumed any of the Trigun story, but from what I remember it was a story set in a dystopian future where local strongmen and warlords battled for control over a desert wastelands while the most altruistic person was targeted by society with the largest bounty on his head in history. Meanwhile the local populace is barely scraping by as they are set upon by both man and nature just trying to survive. So, Western, yes. Sci-fi, (careful of spoilers) yes. Inspirational?
One could argue that Vash the Stampede perseveres despite all the hardships he's had to endure and kept a cheerful demeanor through it all. He acknowledged the harm he's done but is also willing to atone for it as much as he can. For readers who've done bad things in life but want to make up for it, that seems inspirational.
And let's not forget "you need to confess!" Wolfwood's story arc as a mild mannered traveling preacher carrying a cross that's heavy because it's full of forgiveness.
Sarcasm is hard to read in text, but I absolutely agree, but I'm being vague to try not to spoil anything beyond the first couple episodes.