Yes, sellers on reverb are trying to get top dollar. Ridiculously so at times. HOWEVER, it is a platform I really like because of a few domino effect things
1) you can make an offer (unless the seller specifically disables that; lets you know the dude's a tool and saves you the trouble of any business with them)
2) you can let something overpriced hang out for 2 months and them swoop in with a reasonable offer, and a reasonable buyer will take it (again, instant filter for idiot sellers)
It is fair to try to get as much as you can for something; I have no issue with that though sometimes it is ridiculous as mentioned. The community sees that and laughs and posts their similar item for a bit more than they would have and it will sell because it looks good by comparison. But I do love the fact that it is easy to spot the people you should stay far away from (e.g. a known local seller who I won't mention by name; they're crazy and unscrupulous and this has been made more plain via their reverb exposure).
I can see it becoming a problem if people selling on Kijiji start using Reverb to set their prices. There are enough idiots on Kijiji as it is.
How so? Or more to the point, how so more than ebay or anything else? There will always be idiots who use asking prices as their price guide (wishful thinkers) instead of sold completed listings (ebay) or the Reverb Price Guide (which is also good, but I find lacking in that a. it will not let you see the historical listings so as to compare price to condition and b. will not show anything at all for obscure items even if one actually sold recently). Reverb tried to make it better than ebay by explicitly making something called a Price Guide, and that was a good idea (instantly assures that only sold listings are included vs insane asks that end without sale). What I find more useful is using google to search for recent sold listings on reverb after you've checked their price guide. They keep those viewable for a surprisingly long time (vs ebay).