Indoor climbing centres - or gyms, as our friends across the Atlantic like to call them - have a penchant for grade inflation. That's quite a sweeping statement, and I don't mean to demean those centres that are, for the most part, right on the money with their grading, but the vast majority really do go overboard, giving boulder problems, especially, weak grades that only serve to deceive a climber who wouldn't know better into thinking they are climbing harder than they actually are. The reason I wanted to write this as a sweeping statement is that I don't want to single out any particular centres. There are some that are notoriously bad for it and others that I have climbed in that are very good at getting the grade right, even maybe making them a little stiff.
I can understand the other, more commercial side, to this grade inflation as well. Keeping punters coming through their doors is key to making their business work, and what better way to get someone back than to allow them to climb a 6C having only ever been able to send 6A outside before. I always get a high when I finish a boulder problem at my limit or above and if you can instill that feeling in customers they are going to want to come back for it time and again. But this is deception.
Sooner or later, a new grading system will have to be implemented for outdoors and indoors bouldering. An indoor 6C being equivalent to a 6A (I have chosen such a wide gap here to illustrate my argument - you might only be talking a grade or two difference usually) - maybe call it i6C. Or maybe start setting grades properly!
I can't say I enjoy the whole grade debate at the best of times. The circumstances in which it's usually found are new high-end sport route or boulder ascents, which are then repeated and the inevitable debate begins. For the vast majority, however, grades matter, as they show a progression, something to aim for, goals achieved, etc. But this becomes redundant when they are being cheated out of attaining their goal by the deception of climbing something harder than it is. And yes, people can make their own mind up about grades, but only when they've climbed a few problems within each grade boundary does that gain some level of accuracy - otherwise it's merely speculation. What I'm trying to say is that the experts, the route setters, should be getting the grade right in the first place and not asking punters to make their own mind up.