I think the common concensus is that hitting the legend tier doesn't derive enough differences / benefit than the other tiers. Some will appreciate the additional challenge faced from the back tees whereas others will avoid playing ranked rounds to ensure they have a distance advantage in MP games and other tournaments.
I'm personally in favour of these more expensive, high-risk RG's. The inevitable concern is that it'll create a whole new wave of multi-accounters who know that they can focus purely on these big money RG's. They will level up slowly by only playing 1-2 ranked rounds p/day and will be nearly unbeatable if they are of sufficient skill from the short tees.
I therefore whole-heartedly agree that these should be "legend only" tournaments. Let's incentivise people to actually want to get to the back tees rather than knowing they can win 95% of the tournaments available by hiding behind their actual standard of play. People will quickly get tired of spending $1-2K per nine holes if you get a sudden rash of clear multi's winning these tournaments.
This is not a case of wanting the credit rich to get richer; it's a simple way of stopping you're honest, everyday player who wants to compete fairly from getting screwed over by a flaw in WGT's current tiering system.
One key point however is that I hope WGT have plenty of cash to pay for prizes from the premium elite collection. Regular RG winners (the usual names) will be able to probably gain enough credits in less than a month now to take home a $250 gift card...