Agreed, a one handed thrust has greater reach, but i really prefer close fighting anyway(most people do not know how to fight when you really crowd in on them). If you transition from a slash to a two handed thrust as you 'burst' in at your opponent it is an extremely powerful attack. It's just a matter of quickly and reflexively identifying when- and when not- to use such an attack.
If you disrupt your opponents center(knock him off balance), or hit him with a good cutting slash a good two handed bursting thrust is a viable option.
The straight bladed Katanas were rumored to have been used by Ninjas, and are referred to as Ninja-To(no known authentic examples have survived into the modern era). They were also referred to as Choku-to(english translation 'straight sword', of which many historical blades still exist, but that period pre-dates the actual existance of Ninjas).
Regardless, they are in effect no more than a straight bladed, single edged Katana, complete with a 2 handed hilt. Choku-To's share the exact same piercing tip as the Tanto(as can be clearly seen in the above image), and are
extremely proificient for thrusting as well as slashing attacks. The Choku-To is probably the most powerful thrusting sword ever devised.
They were most commonly used in the Kotu period, in Japan.(approx. 200-700AD).