That's one of the reasons. Another reason is foreign documents in maiden name, such as passport. In some countries it's a hassle to update name. And for Indian citizens for example, it doesn't make sense to go through this whole thing if they cannot hold dual citizenship after naturalizing in the US.
Also, an unpopular opinion... The blunt truth is, considering half of marriages in the US fall apart, and this is more likely in the initial 2-5 years, it may be a hassle for an immigrant to change names back and forth. When somebody changes their name at naturalization stage, it's a more consious decision not related to immigration at all. At that point the marriage is typically stronger and one can make such a big change to their identity without a doubt.