I see. If the data on-chain would not increase, then we could expect that the number of nodes would not be negatively impacted. I would be more convinced by those in favor of the change then.

Ultimately regarding spam, I saw a post from Sjors I think saying that to get rid of useless data (by useless I mean unrelated to Bitcoin as a payment network), a deeper change in the consensus mechanism or soft fork would be needed anyway.