Well, as long as they don't turn back to their spammy activities after having their merit, that's not a bad idea at all, but honestly, I doubt it.
The fact is that, if you've been a spammer for months now and you delete all your spammy activity in order to get some recognition for a 10 minutes-effort, it doesn't seem legit to me, and also, looks like quite against the spirit of the new implementation.
But whatever, the point is: if you change your attitude then, please, keep the new one for good.

I've seen many new one-merited Jr Members, some of them even underserved. For instance, I received a PM yesterday begging for merits with a link to a plagiarized thread as the one the user thought to be meritable. Sadly, he has been merited now, and the plagiarized post deleted:


That's what many are doing. Just to plagiarize a post and then, after obtaining their merit, deleting it. So, if we don' t have their previous activity to judge the natural behaviour, how are we going to suspect of the new threads they make? Do not forget that many people are committing plagiarism from translations, meaning, using an article in their own language as a source and then google to make a translation. This is hard to detect, so the context seems pretty important to me, though.

Of course, the idoneous situation is for them to forget about being spammers and to become useful people in here. But... isn't it quite utopic? I hope some will do this, but I honestly doubt it to become the general behaviour.