I find that the only reason marijuana can be construed as a "gateway" drug is because of its classification as illegal.
When someone has to break the law to get it, he's dealing with criminals. Criminals will sell you anything they can profit with, so if he's got pot in one hand and coke in the other, the person *might* say 'yeah, gimme an 8-ball of that coke, too'.
It's proximity is the only thing that makes it a gateway drug.
I spent nearly 20 years smoking pot, and the hallucinogenics were where my interest laid. Hashish is just another cannabis derivative.
I never tried coke, heroin, opium, or anything else, and never wanted to.
Once it became a paranoid nightmare every time I got high (about 15 years ago), I stopped completely.
The use of marijuana is less physically detrimental than alcohol, but saps energy, initiative, and motivation. A huge number of thirty-something potheads live in their parents' basement, and have little or no aspiration for more.
I think decriminalizing marijuana/hash would remove the rebellious appeal of it, separate it from heavy and debilitating drugs like meth, cocaine, and heroin, and allow for tax revenues from the sale.