everybody who has ever relied on public transport, including trains, knows that the trains that run often bear only passing resemblance to officially admitted timetables. Therefore, making that the basis of any critique of official positions is rather weak.
Incontrovertible facts seem to include
1) The govts foreign policy, which outrages many, including Muslims.
2) The fact that the bombers do seem to have been carrying bombs, no matter how they got to London, they did eventually get there.
3) The bombers cannot have imagined they were doing anything else that makes sense (eg transporting copies of the Koran?), inasmuch as you cannot 'forget' you have a rucksack, can you?
4) Spook foreknowledge of at least two bombers as of interest.
Now, there is legitimate scope for questioning aspects of the official account, including whether the bombers did (or did not) know an MI6 asset. But to leap from that to imply these people were just patsies is not just untrue, but insultingly patronising--for these people believed in something enough to face certain death for it, a fact that cannot be gainsaid. I find it rather interesting that those who get so worked up about this episode have never shown the slightest interest in MI5/SB complicity in the 1999 Soho nail-bombing for example, a still open case as far as I'm concerned. Also, interestingly enough, those agitated about 7/7 do not seem to have anything useful to contribute concerning spook dirty tricks in Ulster either. It would be tempting to see these types as more interested in the X Files, but even that wouldn't be true--as the real life British X Files case (involving Tim Hepple/Matthews) or indeed the more recent fitting up of Ufologist Max Burns that includes a cameo role from two Fortean Times regulars doesn't interest them either.
In the end, perhaps many into 7/7 so much are so exercised by it because it is yet another example of UK subordination to the US culturally & politically. In other words if the US has its 9/11 conspiracy (a matter I'm still looking into) their Brit junior partner conspiracy theorists must needs produce their own equivalent (7/7). How very tedious, & sad.