Because beneath the shrillness
Ah, so you agree it was shrill.
was a laser-focused jab at the tropes of the era (some of which only became worse in the years since PPP,) culminating in the alien screaming about how all of that was the apex of Japanese culture while violating the female cast of the show. It's exceedingly base and offensive, but it makes a very damning and valid point about how anime, especially the medium's predominant fetishes and tropes, depict Japan to the world. You don't get to the ignorant view that all anime is porn without a lot of attention grabbing hentai and pervasive fan service in many export successes building that perception. Additionally, it's only a tsundere short of still being a totally valid commentary on the medium's tropes. Nearly a decade later we're still neck deep in lolicon titles and cheap character design tropes, and it makes no sense considering the medium should free directors to tell more diverse stories, not variations on themes.
Excel Saga makes some of the same points, but not nearly so coldly and quickly. Not lingering also offsets the increased hyperactivity and screaming.
Fair enough, although disregarding the satire and such, there's the ultimate question: Does it make you laugh? I can say that in PPP's case, I got maybe a couple chuckles but was mostly irritated, while Excel Saga only irritated me a little but made me LOL many times. No, not every episode was a winner (in fact, a few were outright duds), but when it was on, it was a riot. Most importantly, I didn't give a lick about anybody in PPP; they felt like vessels to make the satire, not actual characters.
Besides, it's kind of apples and oranges, since social commentary was never Excel Saga's primary goal anyway (at least, not in the anime; I've read that the manga is more social satire-based). It was designed to parody a different genre in each outing, and to that end, I think it succeeded.
Re: The special features: FUNi has been slowly creeping special material back onto their collections (see Gun Sword's re-release), so never say never. Although in the case of Gun Sword, the upcoming set will omit the GunXSword-San omakes, so it may be a situation where they keep some of the special features from the ADV releases and leave some off. If that ends up being the case, I hope the ADVid Notes make the cut.
EDIT: Although, I just realized: ADVid Notes- that's a trademarked item (I think), so wouldn't it pose legal problems to include them in a FUNi release?