I dont think it has anything to do with brand snobs, RRA is a good rifle company who make nice gear. But the Tac carry handle creates more problems than anything. To name a few...
It raises the top rail too high to be used with any mount except one of the weakest mounts you can get... i.e. the X-wide Aimpoint Ring. Am I saying the X-wide ring is crap? No, but it is crappier than several other mounts that are stronger and mount the Aimpoint in a better spot. Using the RRA handle, as you mentioned, also prevents you from flipping the caps down and out of the way. You can flip them up, and have them restrict your FOV, you can mount them to either side, and have them restrict your FOV, or you can just take them off and lose the ability to protect the lenses. You can do this if you want and you're right, its not a big deal really, but that doesnt change the fact that there is a better way. For example,
Get the GG&G Cantilever, the Knights Cantilever or the ARMS #22M68 with the extended spacer. Each of these forward mount the Aimpoint further over the handgaurds. As you may or may not know, forward mounting non magnified dot optics is advantageous for several reasons. It clears your field view, speeds the acquisition of your targets, makes focusing on targets easier and makes two eye open shooting simpler and faster. They will also allow you to flip your Aimpoint caps down and out of the way. These are some of the reasons why so many people like these extended mounts. They actually enhance the performance of the rifle.
Use the RRA Tac carry handle and you have just robbed yourself of all these advantages. And what have you gained? Nothing at all. Any good thing you can say about the RRA handle can be achieved easily and without much, if any added cost with other gear. If you like the fixed iron sight, get one, but get one that only takes up the first one or two rails on your reciever. This will leave the rest of the rails open for you to mount the Aimpoint with any one of the other mounts mentioned. This way you have the fixed iron sight, you have the ability to forward mount (and get all the advantages this entails), flip your caps down, have a fixed back up iron etc.
In the end, there is nothing non functional or necessarily BAD about the RRA handle, but there is also nothing good about it. It is as good in some respects (like the fixed iron and battery storage), but it is worse in many others. The carry handle retails from Rock River @ $190!!! For that price and the Aimpoint X-Wide ring you easily get a ARMS #40 and #22M68 with the extended riser. At which point you would have a much better system for the same money.
Most of us just dont see the point in this thing? For what reason did they put the rail up that high anyway?