I think many are a little too ad-averse. For a little bit of $ you can get traffic that would take months to build organically. Nowadays I'd first validate with ads and THEN go for organic channels.
I think you're right, but Ad blockers complicate matters and make it necessary to have organic more than ever. Google adwords works but my previous employers standard issue install, blocked ads, including on Google, which for a b2b business especially is bad.
Are ads very effective when your customer is a more tech-savvy/developer-heavy crowd? I find that Developers/Tech-Savvy people are significantly more against ads than most of the general public.