Although the OP is probably right as to the reason Frontier did it this way, it's also good to keep in mind that merely removing the compromised rolls would have been only restoring the status quo. When someone breaks the rules, you don't want to just redress the balance, you also need to mete out punishment, beyond just taking away what was obtained illegitimately.
As for damage to Frontier's customer base, it's a lot more hurtful for a game to have a reputation of allowing rampant cheating than to lose a few cheaters.
Unfortunately, as long as combat logging remains rampant, "excusable" and relatively unpunished, Elite Dangerous will always have a reputation for rampant cheating.