Reasons Why People Want Full Respec
There are a lot more reasons why someone might want to respec abilities beyond their last 10 points.
1) Older abilities didn't turn out to be a fun as you expected.
2) Roleplay. Your character underwent a very comic book like transformation that dramatically altered his powers.
3) Older abilities do not synergize as well with your newer ones, and they are now useless or nearly useless.
4) You stumbled upon a new power that is really cool, and it gave you new ideas for a direction to take your character. Older powers are not compatible with it.
5) After a few weeks, you decided you prefer your ranged (or melee) abilities and want to focus on that style of play more. As a result, you need to dump your melee (or ranged) abilities.
6) You thought regen would be fun, but you realized you really hate getting rocked by alpha strikes. So you would prefer a more front loaded defensive passive.
7) You started off playing the game with a buddy who played a healer. He got bored and quit. Now you have no shields and no heals and you really need some. Also, you don't need that offensive passive any more because you are going to be spending most of your time in balanced mode.
8) You used to think PvP was lame and not fun. After all, every other game you played had crappy PvP. Turns out, you like CO's PvP. You'd like to respec into a more PvP friendly build.
9) Knockback didn't seem so bad for the first 20 levels, but wow.... now it absolutely drives you insane. Turns out you really need to switch to a heavy strength based character (even if you are ranged dps) because you really want to cut down on the knockbacks.
I could keep going on, but I really do feel like I have provided a lot of very legitimate reasons why someone would want and need a full respec.
Short version: You do not want players wallowing in regret over level up decisions they made in the past. That won't make them enjoy your game.