No. No no no.
It's a trade off. You sacrifice your level 20 to gain a stat point that affects all of your characters. Do this enough, and you're SO much more powerful.
People that don't understand this, and play at level 20 don't get what this game is all about. It's a grind for sure. Keep at it, you'll get there, like the rest of us who've stuck with it for months.
As soon as you hit 20, just promote. You'll be level 20 again in no time anyway (2-3 hours if you've got a good Perilous group), or if you need to pug, run a few games in Threatening to get level 7/8, or 10 and then go back to Perilous.
Or, spend 1 day getting a ton of characters "Perilous Ready" and get all the ones you want to play around level 12-13. Then later, get a good group that will continue grinding out some Perilous. Promote one, switch to another class, promote that, switch again.
There's so much of the current game that we have that needs to be fixed. Don't whine about wanting free xp so you can play a level 20. That's a waste of the Dev's efforts to make this game better.