Inn!
Express!
Breakfast!
Clean!
Rooms!
Holiday Inn Express might have beds fit for a Baggins, but everything down to the fold of the sheets and the pen/notepad is the same every time, and I cansure appreciate that.
Last AirBNB I was at told me to just not smoke all the 'courtesy items' on the shelf left by previous tenants.
Nice people, but just not what everyone might have in mind as far as accommodations go. Or maybe it is, who knows.
In a non-tourist marketplace you get lots of repeat customers and not too many inflow of new customers. So merchants are highly incentivised to provide decent quality service/product. If not then they won't get repeat customers and there aren't too many new customers to keep their business running. There's also a kind of word of mouth review. So chances of fake products and scammers is quite low.
Tourist markets on the other hand are exact opposite for reason you have already explained. And an online marketplace is essentially a tourist marketplace. There's a good reason Apple is so ruthless about Appstore moderation. They don't want it to turn into an Amazon like marketplace. The irony is Amazon's unique selling point was that they are not Ebay in that they would vouch for the quality of goods being sold there. But now in search of profit Amazon has become Ebay. And this is how every online marketplace will be I have seen way too many of them.
With AirBNB and tourist traps, there are no refunds and the nature of the sale/service means you often can't find an alternative if you've decided to take the loss.
Tourists traps excel on this niche of scam. They serve bad food at high prices, but quite often not so bad or expensive as to be illegal. The only reason this business exist is because most people would visit them just once, customers are replaced each day with new arriving tourists.
Everybody is a clueless tourist in the sea of Amazon products, applications in the App store or literally on Airbnb. They only need to sell once to a very small percentage of Amazon customers to be very successful, even if they never come back for obvious reasons.