Well I don't think it's a dumb idea.

Obviously.
We have a lens review section, but it's not as active as the lens forum. And people have a propensity to name their threads in non-descriptive ways like "look what I just bought" or "LBA strikes again", which doesn't tell much about the content of the thread.
Or, as in the tripod collar thread, contains extraneous, yet interesting or valid information about a specific lens' attributes and performance that isn't hinted at in the headline.
I like the "club" threads because they concentrate specific lens topics into a thread that will immediately tell you what to find inside.
Which is basically an extended lens review that promotes a more nuanced discussion besides what you might find in the review section like "I just paid a bunch of money for this lens and that's probably why I think it's at least 8.5 out of 10" or "this lens sux 5/10".
I'll agree with the other poster and say that perhaps it's better to have a "star*" club instead. . . .but on balance, I prefer targeted threads.
my 2 cents.
I'd like to see more 'club' threads. Lenses that don't have a large user base will dither into obscurity -- but lenses that have a dedicated user base will thrive. And if you're looking for information about a particular lens, how it's used, and what people are doing with it, the specific threads are very pleasant to browse.