Sounds to me like you've never done a mid-budget level all inclusive before.
Plastic cups for drinks - normal & typical
Buffet food - normal & typical
Humidity and musty smells - you're in the tropics, hello!
Hard beds - very typical to Mexico, not just this hotel
Vendors - very common throughout most of Mexico, is this your 1st time there? They are taxpaying permit carrying salespeople, don't want to buy from them then say no thank you...simple as that.
4 stars by whose rating? Your travel agent, tour company, or is it the hotel's own website touting this number? I ask because the star rating system is NOT uniform in North America...a 4 star in the US is different than a 4 star in Canada and very different than Mexico so I wouldn't be placing all my reliance on this.
My other question is - did you complain to the hotel themselves about the drain, the air conditioner, the fixture issues, the dining reservations? Did you ask to be moved to another room, or speak to the front desk or manager about the reservation system?
Not belittling your experience, but did you do anything to remedy the situation while you were actually IN Mexico, or just wait until the safety of the anonymity of the Internet to come back, register a nickname at random PV message forums, and blast the place?
If you bought a cheap package deal, you got what you paid for - a cheap package deal...standard room, buffet food, national brand drinks. It's not Club Med after all.
