Yes, but it may be worth it, particularly if the guy likes the feeling of hair on his body. It can get in the way, get stuck under either partner, and end up everywhere. You'll find that many couples where the woman has very long hair will braid her hair before sex to keep it out of the way. A lot of these women braid their hair every night to sleep anyway, and the braiding can become part of foreplay. Some guys also like to pull on the pigtails. Typically she won't wear it down except for special occasions where they plan to use her hair during sex. A woman who knows what she's doing can work wonders using her long hair as lingerie and against her partner's skin. That can be great, but the hair will have to be de-tangled and brushed out after.
After they've been together for a while, a couple (or just the woman) may decide the long hair isn't worth it. You'll notice a lot of women do chop their very long hair around the time they become sexually active or when they become regularly sexually active with a single partner (e.g., at marriage). Truthfully, a "boy short" pixie cut is the most practical style for frequent sex, but some guys do not find the style particularly feminine or sexy.