This is an old and valid argument. In many cases, some raids or instances just require a certain level of gear in order to beat it. Take Archavon, for example. He's the easiest raid boss in the game, but players will need to bring a minimum DPS in order to kill him before he enrages. It's a simple fight, and players don't need much skill to do it (step out of the clouds), but there's just a modicum of gear required to pump out enough DPS to beat him. No matter how good you are, weapons and gear scale your DPS upwards or downwards and there's a ceiling you just won't be able to break.
On the other hand, no matter how well-geared some players are, some AFK their way through things and that's just not the kind of player you'd want on your team, is it? Gear isn't an indication of skill. It's just an indication of what a player is at the minimum level. Unfortunately for Bell and other skilled players, there's nothing to quantify skill as easily as gear. The closest thing would be to lay claim to either The Undying or The Immortal as a healer, but even that's no guarantee (but it's pretty damned good!).
This argument of gear vs. skill isn't going to end, really. There are merits both ways. All Bell asks for is that players should give other people a chance. So while the struggle to obtain gear might be arduous for some, getting there will be part of the experience. A good player will always make an impact to a group, particularly a good healer. True enough, skill will always outweigh gear, but a skilled player will always get good gear in the long run. Needless to say, a skilled player in excellent gear is the best combination of all.