GC takes a serious beating on this site, and often for good reason. I too have had my issues, inexperienced sales people, catering mostly to beginners, etc.
But I'm going to commit a cardinal sin on this site and say this...
In defense of GC, if I need a drum head, pair of sticks, particular bass drum beater, or an odd size case, ASAP - I know I can do a GC drive-by and usually get what I need. In addition they do a good "used" business and I've gotten some good deals on stuff, mostly because they buy so low, sometimes not knowing what the price should be, and I benefit. I will often walk my students through drums and help them get into a first kit - and negotiate a few bucks off.
I live near GC and stop in once or twice a week and find the drum shop folks to be helpful, polite, and in most instances eager to learn what they don't know. (I have met a few butt-heads, not many)
Let's be realistic here - it's a business, in business to do what businesses must do - make money! That means, buy low, sell high, cater to the largest market of customers, and sell what people buy, it also means you can't pay huge salaries! Which translates to a rotating staff of younger folks who may be less knowledgeable than one of us!
Guitar center has sponsored many of my drum clinics and events and loaned me tens of thousands of dollars of gear over the years. They've also inspired many young drummers with the Drum-off.
Guitar Center is what it is and it does what it does well. I can't fault GC for not being a small locally owned shop with lots of drum expertise and years of experience or selection in vintage or high end gear, any more than I can fault my favorite local shop for not having millions in inventory, or thousands of square footage!
There I said it!
