Just trying to get the facts out to the readers. The statement:
[color:"orange"]
the entire coast from Cancun down to Tulum into an endless strip of mega resorts and "eco adventure" sites[/color]

Isn't accurate. The OP came off that and narrowed the focus to one area only:
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the area directly around the Tulum archeological site has been turned into a cheap theme park
[/color]
Redacted even further by:
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...perhaps the description "theme park" was not correct.[/color]

Refined the original post again to:

[color:"orange"]massive car and coach parks, pavements lined with cheap souvenir shops, hordes of shirtless tourists,[/color]

Now asking for a snapshot of the parking lot of a major tourist attraction at the busiest time of the day:
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post a photo of the car park and shopping/restaurant area around midday[/color]

For those who have read this far, Please know that the area around Playa del Carmen is an active, vibrant, safe, beautiful and diverse tourist destination. It's easy to get to from most parts of the US and Canada. Most of the economy here is built around the service industry. Therefore they take VERY good care of the tourists. This area is growing and improving everyday and not in an adverse way.