1) You say that pool players are better now. I know why you FEEL that way, it is a human trait to associate yourself, your generation, your people, your WHATEVER with the best.(
http://en.wikipedia.org/wiki/Illusory_superiority). Now, in the case of ATHLETIC sports there is actual scientific reason why athletes are better now. In the case of pool however, there is absolutely NO advantage players have now other than the wealth of knowledge out there. Knowledge will only get you so far. It wont set you a 50 year record.
2) According to you there is a very large number of pool players worldwide. Well, this attests to the difficulty of beating this record, by the fact that no one has. Surely any self-proclaimed straight pool player is going to try their DAMNEDEST to beat Willie Mosconi's 50+ year record. Why would they not?
3) You say people have already beaten the "difficulty" of the record in other ways. This is 100% subjective and you know it. Arguably the hardest aspect of running 526 balls is luck. Any long run of straight pool involves getting some rolls.
4) Tight pockets are tougher to make balls in, I agree. However the rest of the "playability" of a nice diamond table makes everything else easier. The table does what it is SUPPOSED to do every shot. Regardless, the difficulty in straight pool lies with the game itself: patterns, position, and break outs, and most importantly, consistency and concentration.
5) I'd like to know, how did all of these supposed "more difficult" runs end? Did they end on a rattled ball? Or did the player get out of line, dog it, make the wrong decision. etc. If it was the prior how do we know it would have went on the 8 foot with buckets?
In Summary you are belittling a record that has stood for over 50 years because you like to believe you live in the "best" generation of pool players ever. This can't be proven and is irrelevant. Every player since the record was set has had and still has the opportunity to use the same exact "easy" table yet still the record hasn't been bested. One day someone will beat the record, but until then I'll just keep listening to the excuses, what ifs, and apples to oranges comparisons.