Since the topic seems to be switching over to a change in the runner aspect...
Although I agree that the means and ways that humans obtain the runner reward during matches these past months or so since the change should become more challenging and harder to obtain...
...I do not believe we should actually make the amount of blocks used or modified to a zero amount.
Why?
The following are all basically biased, and may or may not have happened to anyone else, but I find it a bit relevant to problems with a 0 modified runner.
1) I always seem to find that near the end of a round that I'm attempting to run on, or just about to pass the block restriction to achieve the runner objective for that single round; I always find that, due to the mouse being used as the primary way to turn your characters (Steve's) vision around the playable map / world, there is always, and usually is, a slip of the finger to build, or modify a specific block. This is a small, and not that important of a reason honestly.
2) There seems to be a peculiar glitch. I've only seen this happen with the WoM client, mainly as I have not used the browser in awhile due to its Java and my unwillingness to downgrade it to an earlier state: But on occasion, normally half-way through a round after deleting many blocks at a time, the game seems to transit into a state of constantly placing the current block I have selected in my hand. It goes a rapid state, and only seems to go away after I restart my client. Again, a small reason.
3) Finally: Some maps, I feel, need the idea of modifying blocks to survive. Many maps usually have large walls (like mouse, or off), and others require blocks to be deleted in order to uncover other zones of a map: such as deleting the netherportal on realms in order to get into the "nether-section." Also: many times when a player is running, it is fairly easy to find ones-self trapped between the zombies, and a section of the map. Runner options, when modifying certain blocks, also allow certain areas of the map to give that runner an edge against their pursuer. Runner options should give leniency away from moderating blocks.
Although: I think that changing the number of blocks placed, as it was before, the best choice. 4-7 blocks possibly depending on the map. (Mainly varied due to the glitch / slip of the finger arguments stated above.) If it is decided to make runner a no-modifying response, I think that aspect should be included more in “hardcore” rounds.
Again note: This is my opinion, and is biased. I do not know if similar opinions / experiences in terms of the glitch and slip-of-finger exists. However, they are all only suggestions seeing the question in which the topic is going toward (As the original question seems answered enough).