Hey guys,

I am coming from a B2C background where the first rule of engagement is that you only email people who signed up to your communication in some ways. Best practise. Easy.

I am just starting a job in B2B and I don't really know much yet about this environment. I am looking at softwares like Salesloft that B2B companies are using to gather people who might be interested in their services.
Salesloft won several awards being innovative, they pride themselves on building high-quality prospect lists. Big companies like IBM or Oracle are using them. Yet I couldn't find a single article, forum comment etc. on why is using a list building software like that is bad. I see the merit on collecting more information about prospects for a 1on1 sales talk, it just makes the work of every sales person easier if they have more intel.
But for email marketing...
Is it just me who thinks that this goes against the main principle of permission based email marketing? Is it technically illegal to send to a such list in most countries? (USA excluded as they have an opt-out policy)

Or is this different in the B2B scene? It feels this is more accepted or even encouraged.
What is your take on this?