Toiling Tuesdays: Two Thoughts

Someone once told me that to rise to the top you had to be promoted. To be promoted, it is faster to take promotions from other companies because your own company cannot always view your potential. But if you are always changing companies, wouldn’t you theoretically start at the bottom?

            Why is it that employees who have been with a company longer get more vacation time but are more integral to the company and therefore can’t take time away as easy or even at all (a la phone available during vacation) whilst new employees who aren’t that important get no vacation time at all? If I work longer and harder at a company I’m rewarded with something that I can’t fully take advantage of? Why aren't I given the option to sign a contract with the employee stating terms on my end as well as theirs, such as I'll commit to a year and they immediately commit to benefits and insurance, yadda yadda yadda...