Why was the VC10 unusually prone to reverser-induced buffeting? According to Wikipedia, the original (“Standard”) version of the Vickers VC10 had thrust reversers only on the outboard engines, as putting reversers on the inboard engines produced severe tailplane buffeting and attendant fatigue problems.  The larger, heavier Super VC10 had modified and repositioned engine pods in order to resolve this issue, allowing the Super to have reversers on all four engines; despite these changes, the buffeting from the inboard reversers proved to still be severe enough to necessitate their near-immediate removal.

In contrast, the vast majority of jetliners with tail-mounted engines (leaving aside oddities like the F28, which has no thrust reversers at all, and the Il-62, which has four engines, with reversers only on the outboard pair, like the VC10) experience(d) little or no trouble with reverser-induced buffet, even though their engines - like the VC10’s inboard pair - are (or were) located immediately adjacent to the empennage, and, thus, should be just as prone to inducing buffet as the inboards on the VC10.  1-11, DC-9, 727, Tu-154, F100, CRJ900 - all have (or had) tail-mounted engines with thrust reversers, but none experienced the buffeting problems seen with the VC10’s inboard engines.  Why is this?
It may just be that other airframes mount their engines with sufficient clearance to avoid the buffeting issues that were seen on the early VC-10's. Ultimately it only took of a move of 11 inches to solve the issue 


  ...testing was prolonged by the need to move each engine pair 11 in (27
  cm) outboard. This major redesign was needed to resolve tail-plane
  buffeting and fatigue issues due to thrust reverser operation. The two
  inboard engines could have thrust reversers installed at last,
  matching the 707.


So while it may appear in photos that other aircraft have similarly mounted engines you would need to look at actual technical drawings to truly compare mounting distances. 

Its also worth noting that there is nothing saying other aircraft do not also see buffeting from their aft mounted thrust reversers, however they may not see enough to cause structural issues as was the case with the VC-10.