I don't think anyone said a 500 foot gate was dangerous per se. BA had a 500 foot gate for ages and everyone grumbled when it went up to 1000 feet. Properly briefed and planned a lower gate is perfectly acceptable. In BA there are lower gates on certain approaches, but the exceptional nature of those approaches means that people are very focused as they fly them, energy management has been thoroughly planned and a missed approach is considered a high probability.
What has perhaps rankled people is the idea that the 500 foot gate is a target rather than a limit, and the implication that those who don't choose to push the limit are in some way inferior pilots. I'd suggest the idea of a slick approach to 500' being in some way impressive is the aviation equivalent of the boy racer trying to drag race you away from the traffic lights. The nob in the souped up Vauxhall Astra might think he's 'beaten' you away, but the reality is you don't care because it isn't a race (although if you did care and floored it you'd probably leave him for dust anyway).