I think women definitely have it better in terms of quantity, and probably quality as well.
There's a part of me that thinks it's somewhat because most of the companies making sex toys are run by straight men.
However, I think it could also come down to the simple anatomy of things. Basically since the earliest records of human's using tools there has been evidence of female sex toys. Stone, wooden, ivory dildos. Finding something that can be inserted into a hole is a lot easier to come across or design than something that fits "just right" around something else ie. a man's penis.
And when it comes to male insertables or anal devices, I think it's probably a matter of demand. When anal dildos and vibes are designed specifically with men in mind, they can become less appealing to women, and vice versa, so most are designed to appear gender neutral. And although only a fraction of straight couples have reported having anal sex on a regular basis, they are much greater in number than gay couples who report having anal sex. Now, there are many a straight man out there who enjoys having his bum played with, but fact remains that MOST of the time, women are the ones being penetrated. And again, because the majority of women do not engage in anal play or anal sex, and neither do most men, so of course there are going to be fewer toys designed for anal use.