Shareholders invest heavily in infrastructure especially in the rail network - those flashy new trains, fuel, track upkeep, maintenance and technical investments don't pay for themselves. People risking their own money want their dividends and some form of return. Any money left over is then wholly reinvested i.e new stations, staff and further development as well as ongoing salaries.
If you invested £10,000 in your corner shop to buy new fridges, an advanced ePOS system sourcing new products from alternate suppliers, you wouldn't expect your money including any profit margin to suddenly be absorbed to pay staff a pay rise who are paid above the retail average.
There's a generalised stereotypical negative view of shareholders in this country but people don't realise their impact from transport advancements, innovative technologies and more importantly job creation. They may make a lot of money each year from their dividend but that doesn't mean it's a profit or their money back entirely. Some HS2 investors wont see their money back they invested 10 years ago until the 2040's.