There are enough reports out there to make me think there is an issue, anecdotal or otherwise.
Both of those end user groups (LEO/Mil) don't use their own funds to buy/use most of their gear, so they frankly don't give a shit if something breaks they just bring it back to the armorer or supply shed and get a new one. The types of units that are issued the SCAR are also not the type to blab on the open internet about design flaws of issued weapons. Who does care about it are the armorers and logistics guys who are managing budgets. That a few electro-optical devices had to be "redesigned" to work properly with the 17 tells me there was/is an issue there that was costing someone, somewhere, enough money to make a redesign financially worthwhile.
Contrast that with civilian shooters who pay for the gun/optic, and ammo to shoot it. Those guns are under a much less severe duty cycle, and even then there are enough reports of optics failing or other strange happenings (mounts recoiling themselves loose) on any number of forums. M4C, LF, FNForum, Arf, etc.
The schools of thought are:
1. Cantilever mounts flexing during recoil
2. Forward "recoil" impulse of the massive 17 bolt/carrier which many optics aren't designed to withstand.
Personally I think the primary cause is #2, which may or may not be exacerbated by #1. Spring loaded air guns also have a significant forward recoil impulse which can damage optics. To mitigate this, scopes which are designed for severe or military service seem to be able to withstand it better than other types of optics though at what type of duty cycle I'm not sure.