Oh please.

You ignored all my points and threw in a cheap shot at Pentax. (Obviously you're not familiar with Pentax lenses if you're inferring that somehow Minolta/Sony are churning out superior lenses. I just today read DPReview's two new Sony lens reviews, for a couple quick examples. And note that my only F2.8 zoom is a Tamron, not a Pentax. As for ISO noise... well, there's only one DSLR that I'm aware of with clearly superior high-ISO performance, and that's the D3. OK, are we done with cheap shots now?)
Zooms generally have more issues with vignetting, CA, PF, barrel distortion, edge sharpness, and so on than primes. This is true of all zooms - compromises must be made. Try reading some different lens reviews at Photozone or other places and you'll see that this is a universal issue. Even the finest four-figure-price-tag lenses have some of these issues to one degree or another, more so than most of the primes. Example: Canon's 70-200mm F4 is possibly their finest zoom, yet compared to their 200mm F2.8 prime, the zoom at 200mm has more pincushioning, vignetting, CAs, etc. The 70-200mm F2.8 is better than the F4 zoom in terms of barrel distortion but worse in terms of resolution and CA. The F4 zoom actually does beat the 200mm prime in resolution, but that's about it. And the prime is over 10 years old!
The key point, though, is that I (and anyone with a similar prime lens, no matter the mount) am getting
two more stops with an F1.4 lens than an F2.8 zoom.
You
might be able to get a few good Spectro shots with F2.8. Maybe. If the parade is moving slowly or near some lights. But good luck getting any on-ride shots - like PotC, HM, Peter Pan, etc. Even shots of relatively dim interiors (like the Mission Space postshow game area) will be a challenge with a zoom. The point is - Disney parks offer several situations where 1600 ISO + F2.8 are just not enough, and most DSLRs with a zoom will either max out there or produce quite noise 3200 ISO shots. Not at issue with a fast prime.
Then there's the issue of deliberate small DoF shots (and that primes usually have nicer bokeh)... or that a zoom at F2.8 is at its softest aperture while a fast prime at F2.8 is already stopped down and usually producing extremely high resolution.
Then there's macros... good luck finding a zoom that'll do 1:2, much less 1:1.
Etc, etc, etc.
The only real
problem I have with zooms is that you're stuck at F2.8. At a Disney park, there are many times where I would rather have the extra 1.5-2 stops that you get with a fast prime. You can crop later; you can't make the camera capture more light later.
If you would rather have a zoom, that's fine. If you think F2.8 is good enough, that's fine. But obviously many disagree, based on the popularity around here of fast 50s and lenses like the Sigma 30mm F1.4.
For telephoto shooting, I'd probably go with a zoom since you usually don't gain much speed - 200mm primes faster than F2.8 are pretty rare, so I'll probably skip the 200mm F2.8 and go for an F2.8 70-200 zoom. (I already have a 70-210mm F2.8-4.0 zoom which can be used at F2.8 on my DSLR at 210mm but AF would be nice for such a lens.)