Consider calumnies. A calumny is a “falsification or misrepresentation intended to disparage or discredit another” or “false charges brought about to tarnish another's reputation or standing”. Related words include obloquy, aspersion, slander, defamation, slur, etc.
Edit: In the context of filling in a word for the latter part of “Stop giving «Negative ideas without any reason»” one might say “Stop giving evasions”, although that's a bit clumsy and a native speaker is more likely to say “Stop evading the question”, “Stop giving excuses”, or “Stop caviling”.