webmasters as in single operators of httpd somewhere, no, not likely
other network operators who are recognized ASNs and go to NANOG or RIPE or APNIC conferences and meet people face to face, yes.
if you wilfully disregard valid human-written abuse complaints coming from other equally-clueful network engineering persons at other ISPs, you and your ISP will acquire a tainted reputation.
there's various industry back-channels that exist between ISPs to communicate with each other about this sort of thing, I won't go into many details, primarily because there's a high degree of interest of the parties on all sides in keeping the email inboxes and phone numbers uncluttered with clueless single-residential-last-mile-user complaints about their wifi not working right.