Why does TFS only support 1-to-many Predecessor /Successor relationships?

The TFS task tracker only supports 1-to-many Predecessor/Successor relationships (docs).

I totally do not understand why is so.

For me it’s obviously a many-to-many relationship, since a task may be blocked by more than one predecessor tasks.

This is the first and only time I’ve seen such a restriction in such a tracker (for instance, Meistertask supports many-to-many).

Since I can’t think of any technical problem to do that (it should be trivial), I’m pretty sure there is a real reason for that. I’d just like to know that reason: I guess it’s public, but I couldn’t find it.

Note: this is not a rant. This is a very specific question, that may very well have a known answer (although it’s possible it doesn’t). If you think this is a rant either you misread it, or I miswrote it, or a combination of both.