extremely angry: Can anyone shed some light on the issue?
Hopefully someone with more light shedding power than I comes along soon.
Having also dealt with ITBS multiple times, I'd toss in:
(a) downhills
(b) running hard
(c) pavement
(d) and especially, running hard, downhill, on pavement
(e) wrong shoes, especially with too much pronation control gimmickry
(f) (maybe) tightness elsewhere: quads, hamstrings...
(g) relative inexperience... over the years as muscles but also tendons have strengthened, I can get away with a lot more than in my first few years, even plenty of fast pavement downhills
That's kinda scattered but my point (hypothesis, at least) is that while some factors are under your control - you can optimize your shoe choice via trial and error and training, and you can be careful combining downhills & pavement & speed - you cannot eliminate some amount of hard running if you want to improve, and nobody starts his running career with legs hardened by 10,000+ road miles. I'd suggest you view stretching and the foam roller as useful adjuncts that allow you to train more and better than you could without 'em, and not as kludges only useful after you've failed to avoid some simple "root cause". Next year you may need 'em less than this year.