Not "we", a fairly small number of completely anti social people who are happy to destroy a resource for others if they can make money.

Because we don't punish the spammers. And by spammers, I mean the big "nice" players too, like Google and Facebook.

We tolerate them, and every year they grow a little more evil and audacious.

We did this to ourselves by not making our systems Sybil resistant or DoS resistant. Bitcoin solves this problem by requiring a fee to submit a transaction to the ledger (Denial of Service). lightning does this by requiring you to select who you network with (sybil). Solution is for any modality is to restrict to known good addresses, and for anyone else charge a substantial fee.