I can give you one proper argument on how respecs will unbalance the game.

METRICS

CCP relies on the constant stream of data to determine which weapons to balance out with either a buff or a nerf. We have already seen first hand what happens when too many people spec into one thing. Heavies come to mind and those heavy players who have been here since closed beta will confirm it for you.

Back then heavies reigned supreme and thus almost everyone specced into them. As a result, after so much QQ in the forums about it, the heavies got nerfed... big time. So much nerfed that they became useless for almost an entire year until early last month. Laser Rifles became the next victim and even the tanks. Now the ARs are in the cross hairs and the Logibros are raging over the possible removal of the light weapon slot because people kept complaining that too many logis are acting like assaults.

As you can see, when too many people spec into one thing, it can skew the data for CCP to rely on. Paid Respecs will just add to the problem when almost everyone pays their way into speccing into the next flavor of the month. Seemingly "ok" weapons become seemingly "OP" and seeming "UP" weapons get "overbuffed" instead while the seemingly "OP" weapons get "overnerfed". This will just further hinder CCP's ability to properly see which weapon is actually OP and which ones are actually balanced.

I'm not sure if Atiim described it well, but I can say this...

Militia suits in the hands of skilled veterans will wreck Proto AUR suits any day.

This isn't a respec problem it's a game balancing problem. If the games balanced respecs won't be such a big deal. Respecs would be more helpful to this dying game then it would hurt. Remember this is playing on a soon to be obsolete system, it needs all the life infused into that it can get.

LOL you just described the exact essence of pay to win. You pay to get ahead. Don't have that level yet? With real money you can! I have 16 mil sp I know a little about the game, it's pay to win. You can sugar coat it all you want.

And as someone else already pointed out, you have entered a culture that is famously known throughout the MMO industry as New Eden or the Eve culture. This culture has three basic rules that have remained unchanged for 10 years.

1. Adapt or Die
2. Don't use what you can't afford to lose.
3. Accept the permanent consequences of your choices.

Your choices here have to matter. I have skill points invested in books that I don't like but I have to live with that mistake. In fact, I'm glad I made that mistake because it taught me how to be careful with my choices. Besides, ultimately those wasted SP became an investment instead in case the skill books they affect become balanced again.

Without this third rule, no one will learn anything. We practically live in the harshest universe in MMO history. Welcome to New Eden.