That's why if we don't have a strategy or don't know how to collect data that helps us analyze the competing teams, we will only choose teams randomly. And if that happens to us, we should choose a single bet so that we don't have trouble choosing a team.
If you don't have a strategy and don't know how to analyze teams and players, doesn't matter if you choose a single or multi bet, the trouble will be the same for both betting styles. When a gambler isn't educated enough on sports' matter, he should just avoid it until he has enough conditions to make a coherent analysis of the match scenario, that will potentially lead him to a winning.
For an uneducated gambler that is still possible to happen within time, effort, patience as he develops learnship and of course, since he has a legit interest for sports and think it's an entertaining subject.
It does matter and I think the post of the OP proves this point, even if you do not have a way to beat the house edge, the smaller the house edge that you face the better as this means that over the long term you will lose less money.
So if you only choose single bets then you will lose less money than with multi bets, and regardless of whether you play for fun or profits, choosing the bet with the smaller house edge and losing less money is always the best option.