I only saw a handful of shows, all online. I dunno if I'd say it was the most innovative show in the world (from what I remember, Paranoia was doing a lot of the same thing 13 years prior), but I liked what Scripps tried to do, even if it only aired in a handful of markets. I doubt the reasons you came up with are why viewers tuned out.
From a financial standpoint, the show most likely cut the top prize because the budget wasn't there; they'd wanted to go national since the beginning, and since that never happened, they knew they didn't have as much to work with. Still, to get three years out of it and it never aired in LA or NY is a pretty nice run. I'm sorry it never took off nationally.
ETA: Chris summed it up perfectly; it was an inoffensive way to spend a half hour, but it wasn't a show that had me glued to the set. If it airs vs. Jeopardy! in my market, Alex prolly wins every time. At least Celebrity Name Game intrigues me enough to flip over every so often.
I doubt the stations that replaced Wheel or J! got those shows' ratings, but I would like to see how competitive LAA was, esp. in the early evening time slots.
ETA II: The top prize was $37.5K in season three, down from what, 50K in season one? You do realize that's still pretty solid for a syndicated game show that aired in roughly 10% of the country? Especially when you take into account that the national shows don't even give that away on some days. It's not like they slashed the budget to $5,000 and a Ford Fiesta.
But again, I doubt people were tuning out because the top prize was cut by 1/4. Millionaire hasn't given away its top prize in years, and still does all right.