It doesn't make things worse. If you need to process large amounts of data, the way to do it is to split that job over a number of frames. The editor could/should be modified to do this, probably pretty easily.
MTA is single threaded, and needs to keep an active network connection running, so it can't allow anything to take too long in it's update loop. If one frame took 2 or 3 seconds (and MTA allowed that), it could make all the players get disconnected from the server as they might think they've timed out from the server. Obviously they'd also get no packets in that time, so everyone would seem to stop moving or jitter around for 2 or 3 seconds.
You can think of MTA's aborting of long loops as a very primitive kind of multitasking. MTA relies on cooperative multitasking to allow all the resources to work together, with the long-execution cut off being the enforcer to ensure resources get along properly. Not that there aren't nefarious ways to get around that if you really wanted to break the balance of the system.