...Huh. On the one hand, this is a REMARKABLY different stance than what we've seen the mangaka take on some things. The repeated theme of debt, of circumstance, of the exploited poor who need to keep working these terrible jobs because society has decided that those with money should get to sacrifice those without money to eldritch gods in exchange for more money. They will literally take your soul from you if they can.
On the other hand, this is a remarkably SIMILAR stance to what we've seen the mangaka take in other respects: no easy outs in life, no trying to skip the sourness, you need to do it and you need to do it the right way. Trying a shortcut will only lead to hardship, and reincarnation is certainly a shortcut.
I guess the author's stance is ultimately quite conservative. It's a mix of: yes, you're in this terrible position, but it's also incumbent on you to get out. We've seen this theme expressed more and more as time has passed (consider the other grey workers, who started out solely as tragic and exploited but then later became more warnings, such as the girl who hired a rental family). I wonder if this is a case where the manga's success has impacted the author's view on life. We can also compare and contrast the security guard story (where the "blackest company" works you past death) and the more recent factory worker story (where it's more a story about the workers themselves failing to keep their wits about them).