I used to think like you do and still do somewhat since it happens to me at worst of times. There's nothing more frustrating than good poker being beaten by good luck.

However, I assessed the situation from rational, objective viewpoint and came up with this. Online poker has two major differences from live poker and most people who complain about online poker are using live as a reference. First, there are a hell of lot of bad/beginning players online. For many, this is their first poker experience. Second, online play is many times faster than live so many more hands are seen. This translates into the fact that bad beats will happen at a greater rate and thus "perceptively" at a greater rate per hand played.

As far as singling out Party as the worst, you may be correct. But this may be due to the fact that it is the most visible, largest and most advertised site. Thus, a new player will go there first. More fish equals more people calling to the river equals more bad beats.

Further to all of that, given that Party is perhaps the largest, most well known site, and the motivation of the new players there might not be what you think. For example, we may all assume that a new player is there to be a winning (in a money sense) player. That may not be the case at all. They may just be there for the entertainment and thus the "action". So you can expect lots of people in pots and this translates to flushes and straights being the best hand often. And of course a lot of the time this happens on the river.

I highly doubt a site like this would risk losing their entire business if it was exposed that their deal was not random. They make money regardless of what the players are doing, what cards they are playing, etc.

Any large, established casino would be nuts to risk that, regardless if they are online or live.