> For serious accounts (in the 6 digits/year) absolutely not, unless the attack is large enough to affect other customers.
If it doesn't affect other customers, a hosting company won't act or even be aware, in most cases. They'll just send you a bill for the transfer. If someone attacks you and it impacts other customers, you get nulled. I'm aware of 7 digits/year and 8 digits/year accounts through industry anecdotes that have had machines nulled. The engineer operating the null doesn't say, "oh, that's X, maybe I shouldn't fix the network for my other customers".
There's a bit of middle ground between "sending a bill" and nulling.
I've been hit by two larger attacks in the past (GBit/s range) and the respective ISPs were both extremely supportive, switching our IPs while they tightened their filters. Neither billed us a dime despite our ingress spike making quite a bump in their charts and a lot of handholding over 2-3 days.
If it doesn't affect other customers, a hosting company won't act or even be aware, in most cases. They'll just send you a bill for the transfer. If someone attacks you and it impacts other customers, you get nulled. I'm aware of 7 digits/year and 8 digits/year accounts through industry anecdotes that have had machines nulled. The engineer operating the null doesn't say, "oh, that's X, maybe I shouldn't fix the network for my other customers".
I don't understand what you're disagreeing with.