Nah, Portsmouth is a far more attractive draw to developers who want to plunk down luxury condos with obnoxious gastropubs with chalkboard menus where a waiter with a beard and a gelled quiff will sell you $16 appetizers. I just don't see them putting Old Orchard Beach on their radar any time soon.
Also, that was probably Lafayette Road in Seabrook that you drove through (judging by the abandoned Ames), and I assure you that that's a very accurate impression of that town. It's basically 1A and Lafayette plus a bunch of trailer parks, and both of those roads are a mix of chains, run-down strip malls with facades that haven't been updated since 1996, townie dive bars and disgusting family restaurants, fireworks stores, and porn stores.