The Slash has gotten a bad rap, as has Traxxas in general, when it comes to "hardcore racing". You're going to get a lot of crap if you race a Slash.....I know, I raced one for a few years.
I think what got the smack talk started was when you started your thread on how to get a sponsorship. Like it or not, even if it's where they started, most "serious racers" won't be running a Slash anymore. Of course, there will be exceptions to this, but in most cases it's true. There are just too many better vehicles on the market.
You may indeed find a company that is interested in sponsoring you while you're still racing a Slash. Keep looking, and don't worry about the folks giving you grief.....just make sure you tell them you're driving a Slash when you pass them on the track.