>>rainon+(OP)
Correct. From what I understand, Shodan has had for years a search feature in their paid plans to query for "service X listening on non-standard port". The only sane assumption is that any half-decent internet-census[tm] tool has the same as standard by now.
>>rainon+(OP)
Did I at any point in my previous comment say that using non-standard ports was my only line of defence ?
Its security through obscurity, which puts you out of view of the vast majority of the chaos of the internet. It by no means protects you from all threats.