rotaries can be very reliable engines, i personally know of several that have done over 100,000kms.
Like you said, look after it correctly and they are just as good as a piston motor.
Warm it up, cool it down, make sure it has lubrication for the seals, use mineral base oils not synthetics, good quality fuel, proper tuning, regular maintenance ect.
The things that kill a rotor is no lube in the fuel, hot oil temps (oil is used to cool the rotors), Poor tuning, no mechanical sympathy, poor quality rebuild/parts.
From that, all of those things (except fuel lube) apply to any engine.
There are also people that slag off rotors for blowing up and being unreliable because they heard of joe smith who rebuilds his rotor every year or 2 after a low amount of kms.
What they neglect to add, or just dont know, is that joe's engine is a comp spec highly strung motor that does a LOT of track time.
Same goes for a piston motor used in the same conditions. Full on competition racers rebuild after several runs/once a season. Same with rotors.
Otherwise its in a street car that blew up, because the owner straps the balls off it, it isnt tuned properly and was rebuild cheaply.
Again, a piston motor in the same situation will suffer the same problems, its just better at hiding it for longer.