Mrs. Knott's gets deserving solid reviews -- it's good food served in huge portions at a fair price. I wouldn't consider it to be overrated at all because the only people who rave about it are bloggers who may have received compensation from Cedar Fair in exchange for a fair and unbiased review
. Beyond that, few people or publications will encourage you to stop by unless you're going to KBF, anyway.
There are oodles of similar family style chicken dinners offered around the country. These types of dinners were popular in the 1920s and 1930s, and most of these restaurants have been continually servicing these meals. I imagine nostalgia plays a huge role in their popularity -- it's where you went as a kid, it's where your parents went as kids, it's where their grandparents went as kids, etc. Unsurprisingly, most of these restaurants maintain a rustic look.
Mrs. Knotts likely rose to prominence because their mission was to offer a quality meal at a low price. Those low prices continued until recently -- the adult price was $6.50 in 1988, $7.99 in 1991, $15.99 in 2012 and $22.99 today; children and seniors received deep discounts but in recent years they've become more modest. In the late 1990s/early 2000s, free meal vouchers were often included with one-day admission tickets; if you ate at their Holiday buffet during that same time period, you received either free admission for that day, or a voucher to purchase a future ticket at a low price (IIRC, circa 2000, the buffet was around $20 per adult, gate admission was in the mid-$30s but the voucher allowed admission for around $10).
Mrs. Knotts also opened up several satellite restaurants in the early 1990s. I recall locations in Irvine and Rancho Santa Margarita, but there were others. We ate at the Irvine location several times -- my parents, myself and my brother (both under 12) could eat for less than $20, including tip, with a coupon. The Irvine location is now a California Pizza Kitchen, but still maintains its "farmhouse" look from its Mrs. Knott's days.
$23 is a fair price, but we don't eat dark meat, which increases the price to $27. There are oodles of places in Orange County I would rather eat at for that price, but as I mentioned earlier, we do stop by during one of their Holiday buffets toward the end of the year.
Knott's has long maintained that their fried chicken recipe hasn't changed since 1934. They did sell their food specialty business in 1995. Most products have been discontinued, but the jams and short bread cookies (ironically, the first time I ever had the short bread cookies was from a vending machine at the Caribbean Beach Resort shortly after it opened, when I was a little kid) are still available. Knott's recently re-introduced new products, but they cannot use the Knott's brand name; the press release indicated they'd be available for purchase at Vons and elsewhere but I've never seen them outside of the park. Then again, I don't normally eat that stuff, so maybe I just haven't looked hard enough for them.