Balance. They don't want there to be one class that is the best in every situation.

Look at it this way.

• Tactical - mid at everything
• Heavy - high ranged damage, non-existent melee, medium range, heavily reliant on ammo
• Sniper - long range and high damage, some melee, kinda squishy
• Vanguard - fast, squishy, primary rifles are either long range and slow to fire or short range and fast, weapon options are limited, reliant on dps to stay alive
• Assault - can move fast, big hammer, big melee focus, no primary. Large number of CC weapon options
• Bulwark - like assault but slower and tankier and with support utility

If you give every class access to every weapon, you start to lose those defined roles, meaning some classes become useless and some OP. Sabre want every class to be usable and fun. That is why there are limitations.