It's not uncommon on smaller boats because
It costs the boat builder less than installing sumps and pumps to dump them. However, it also means a wet smelly bilge, because bilge pumps never get the last quart or two...and since ANY water in a bilge sits, stagnates, and stinks, shower water with its body oils and soap scum, and ice box drainage with whatever has leaked, melted etc in it is even "riper." I wouldn't let that stop you from buying the boat, however...you're not likely to find sumps on any production boats in this size and price range. But I'd definitely add them. If you're buying the boat from dealer stock, have the dealer install sumps as an optional add-on... If you're ordering the boat, ask if sumps can be a "factory added extra" when your boat is built. In either case, you'll have to pay for them, but you might you able to use them as bargaining chips in negotiating your purchase price.
