Just because it should be doesn’t mean it is. It’s fully within rules to have any number of free accounts and it doesn’t matter why as long as they are not breaking the rules. Heck these forums were filled with people who were encouraging to make smurfs in early years of HL as way to get out of their imaginary MMR Hell and they ruined games for years in high ELO by abusing the MMR seeding. Something being legal doesn’t automatically mean it’s morally right nor does something being illegal mean it’s morally wrong. People who report smurfs are actually making false reports and breaking the rules.
Devs actively made smurfing easier knowing it would increase smurfs. All they cared about was the “new players” it creates for their statistics. Did you know back when HL was a thing new accounts needed to be confirmed by email or optional phone number when you first login with them? Since SL you can use fake e-mail as there is no longer any validation needed. They also made smurfing easier in-game by lowering ranked requirements for them when SL was created. Everything devs have done that has any relation to smurfs in the last 3 years has been in favor of smurfs. They haven’t done a single thing to make smurfing harder nor have they condemned it at any point(because again, it is fully allowed within terms of service which you have agreed to).