But the for-profit is owned and governed by the non-profit, so overall it's still non-profit. It's probably about the statues of the nonprofit and certainly at least on part about keeping a separation between income (Google) and activities (contrary to Google)
Mozilla Foundation is non-profit but Mozilla Corporation is for profit. I don't know how that would affect your opinion but it certainly did when I found that that out recently when I wanted to know how much they were paid by search engines.