Newcastle fans' issues with Ashley aren't that he's not rich enough, but more that after his initial burst of optimism ended with him falling out with Keegan his approach has been to run it like Sports Direct and tried to cost cut everything (including basic decency around when Gutierrez had cancer). They've gone way down the list in terms of commerical income, it's hardly increased while sponsorship deals and the like have skyrocketed for everyone else. It's not like it's being run well but outmuscled, it's choosing to extract value rather than allow for reinvesting the profits they make. The reason you'd describe them as 'faltering' is down to how it's been run; their previous finishes before he took over were 4th, 3rd, 5th, 14th, 7th. Since then, they've been relegated twice.
I'm sure there's some who only see it in terms of not having any big splashy transfers, but the guys I've spoken to all see it as more the general malaise that comes with trying to achieve 17th as cheaply as possible rather than trying to make progress or achieve anything, and would have seen a steady attempt to get back to the top based on reinvesting money generated from healthy growth as a perfectly acceptable process and were happy with Benitez (who then quit and blamed Ashley).
Wanting Ashley out is a different thing from wanting the Saudis in.