Online forms are fine, but they are no substitute for an email address.
If you want to shop on the Web, you may have little choice. Second, because they want to reduce their administrative burden by forcing people to contact them only in ways that make it easy for them to process inquiries. Even now that Web shopping is becoming more mainstream, most Web sites probably get more visits from other Web business people who want to sell them things than they do from potential customers. Yes, if you publish your phone number on the Web, you'll get calls from salesmen. Anyway, the salesmen will find you no matter what you do, so trying to hide from them only harms your business, not theirs.