If an individual increases their TX power it would help them, but make others' experience worse. In a situation like an apartment block, if everyone increased their TX power then everyone would have a worse experience.

The point of this specific regulation is to prevent tragedy of the commons in a shared band -- if you want fewer restrictions go ahead and license your own spectrum; it wont be cheap.

If anything, it should be responding to new technology by encouraging their use to make use of shared bands more efficient, for example by reducing the power limit and restricting the use of inefficient modulation schemes.

edit: I know the article was about symbol rates, and I would agree that a symbol rate limit is silly, but you're responding to my comment which was just about the power limit.