It gives the bettor safer options than the bookmaker making money off of the bettor's choice, so it is, IMO, a line that is rarely a priority for the bookmaker to place in their platform. Compared to moneyline bets, draw no bet is more flexible in terms of profit in favor of the bettor, and not so much for the bookie. It has its drawbacks though, as it usually has odds that are just not worth it, but since it has a 'draw' mechanic in the bet, you will still take the risk and bet on it since in the event of a draw, you will still get your money back like nothing happened.
I like the second you said about draw no bet 'that they come with small odds'. The smaller the odds the more chance to win, but the more someone play, the more someone have chance to lose huge amount of money. Draw no bet has no advantage than a means betting sites are earning more from bettors because if you have gone for win only, the odd will be more, if you won at ones, you get higher amount of profit, but if it is draw no bet, you can win 2 times and later lose one time which is sufficient enough to make someone lose than gain, though all types are risky but I prefer going for win.