It depends
1) What is the extent of the restrictions (is it just restricting races, or is it restricting races and classes and other stuff to the point where i feel like i can't make something that i'd want to play)
2) What is the reason for the restrictions (is it for flavor/setting reasons that a race/class isn't available, is it simply because the DM doesn't like the given race/class, or is it for balance reasons, etc)
3) if it is something restricted but someone really wants to play it (for whatever reason) is it something that could be allowed with some tweaking (okay so there are no genasi on this world, but could it be a planar being trapped on this world from another plane)?
in my current group, we have a few different DMs and in each campaign that we've rotated through, we have restricted various races, classes, and supplements in different amounts for different reasons. but these all get announced from the get-go of the campaign (and therefore no surprises down the road after people started making up PCs). Usually it isn't really a problem for our group - though it did bother one player every time just at the idea that something was restricted even though he never seemed to want to play those restricted things and occasionally there was someone else who did want to play something only to realize it was going to be restricted in the next campaign lined up. But over all, really not a big deal in the grand scheme for our group. At least from my perspective.