That's what you said in your previous post and I pointed out that it's still reiatsu, but insanely high-level reiatsu that destroyed the cleaner.
Are you asking why they didn't try to get rid of cleaner, so that they can freely move to SS?
If that's what you are asking (again, I may be getting this totally wrong), the cleaner is there to make sure that nobody resides in that separated realm, over the dimension of time and space.
Its not about getting rid of the cleaner, its that it wouldn't make sense that if the thing could be affected by shinigami powers they would have no way to control it. Mayuri is not the sort to pass on that, urahara is not either. Yet what we see is that every time ichigo or someone else has to go to SS they have to run from that even after ichigo saved SS. There is no reason for the shinigami, specially urahara and mayuri, to not want to understand the kototsu. until the manga says otherwise then 10 yamamamoto's with bankai can't do a thing to it because yamamoto is still only a shinigami with normal reiatsu. Gin said it as a fact, the train is not a being of reiatsu, it is a being of reason and thus cannot be stopped with reiatsu.
Perhaps hybrid/transcendal beings have a different reiatsu from that of a Shinigami ? It's not like transcendal beings were being studied and everything is known about them
It's the same way a shinigami cannot interfere with Aizen. Aizen merely went beyond what is logical for a shinigami. http://www.mangapanda.com/94-57474-1...apter-420.html
http://www.mangapanda.com/94-54486-2...apter-409.html Aizen purposely lowered his reiatsu at this point in time to the levels of a shinigami but the humans who are unable to perceive reiatsu can't do a thing.
http://www.mangapanda.com/94-54924-1...apter-410.html Ichigo's friends are able to perceive spirits thus they sensed Aizen's reiatsu when he lowered it.
People can interfere with Shinigami...apparently it's easier to get physical than to see them
So, base Aizen vs Yama, Aizen has the advantage over everybody with his shikia only way to counter this is to grab/hold his sword handle and it won't affect you this is useless given its ability it's a complete genjitsu that he releases after his checkmate, it can be done but not the way Kubo writes as Aizen would just reveal that you were touching an illusion....2nd is to be struck by his sword and then hold on which is practically the same thing but his illusions obviously can't hurt you and that you can feel his reiatsu.......So Yamamoto can survive being impaled and counter attack like how his original plan was suppose to turn out....Or he goes banjos and uses Zankai East/West Whichever cladding him in flame and Aizen from there can only use Kidou to attack him.....So Yama yes he can beat Aizen with Low/Mid difficulty.
Chrysaline Aizen is cocky an doesn't use his shikia ability....Yama Wins this by going Bankia....His Shikia IMO can't land a killing blow or simply would take to long.
Ascended Aizen same thing gets owned by Bankia.....Mid difficulty he was pretty strong I guess =\
Super Ascended monster form Yama goes all out facing an seemingly opponent that is just as strong as he is if not a little stronger but will just keep obliterating Aizen until he can seal him...High difficulty.....
I don't even care who wins Lol xD...Kubo transforming Aizen like that was stupid only Ichigo's complete fusion was Kool and made sense but even he couldn't kill Aizen an still got hurt by him.
It's likely that Soifon hit air than actually coming in contact with Aizen...He was using KS the whole time