You were critiquing the security cost of hosting on your own server verses that other server. It was pointed out to you that the admins of that other server would likely learn of (and react to) a breach on their end at a lower latency than you would for your server.

You implied that the security cost for hosting on your server was actually lower, because you weren't as much of a target. My reply was an attempt to point out to you at a technical level why that was a specious argument; your servers are likely being scanned by the same botnets that are scanning mine with automated exploit attempts against old and vulnerable software, and common errors in securing a server.

It's going to be far easier and cheaper for them to take a shotgun-scanner approach against a large class of average systems than to apply manual, concerted effort against a small set of high-value targets like CDN nodes.

The cost to the attacker to attack your system with automated tools is near nil. They'll attack, and if they get in, that's gravy. Using "we're not a target" as a security model makes about as much sense as putting an unpatched Windows box in your home router's DMZ.