Pros
If you do your job well, then you will likely never have to worry about having a job there though you might never get promoted. You have to be content with holding the same position or remaining at the same level (individual contributor, first line manager, etc.) for your entire career.
Kontras
Politics are paramount when deciding on good promotions. Most senior leaders will not present information to the person above them contrary to what they think that person wants to hear, which destroys shareholder value by their not fighting for what is best for the long term value of the company. Incentive plans encourage managers to emphasize short term results, and to make decisions that at times can hurt profitability and cash flow. Sales is not given enough incentive to worry about profitability or return on assets, leading to shareholder value destroying transactions. The accounting/finance department does not forecast well (due to possible under-staffing), which hurts the incentive plans of managers in the field. There is no up or out policy, allowing average managers to hold key and limited availability positions for decades, which stifles the possibility of advancing more talented leaders and business managers, destroying shareholder value.