You're right that abstracts often have a positive bias that can sometimes border on dishonesty, but for most papers it's not a matter of investors or newspapers, but rather of getting the paper accepted to the conference or journal, especially if it's a highly selective one. It happens even in fields where there is no direct industry interest.
Conferences are often done just because it's a requirement to get grants/continue to be sponsored by an university. Investors are not just VC/for-profit industry, academia system also counts.
