Well melting and vaporizing are two very different amounts of heat.
Melting point, I suppose that depends on what you consider "solid". Lets talk extracts for a minute, trichome contents without the trichome "husk" and whatnot lol. You can have shatter that breaks easily at say 70 degrees but if you leave a ball of that sitting overnite at 70 degrees it might flatten out some. It's still somewhat viscous. So viscosity is the thing we are talking about, a mixture of oils/terpenes that all have various melting points mixed together. So melting point would be going from solid to liquid, but at what viscosity do we consider it a liquid?
Now to melt a trichome is way harder than to melt an extract. Think of trying to dab kief. lol That extra cellular "material" doesn't wanna melt.