The key word is "planning"
I've been reading of Space Tug PLANS for about 20 years. To date, it has all been vaporware. Sure, there are a lot of good ideas that can be done but none of them appear to be within 10 years of flight hardware. Plans are like anal orifaces - everyone has one. Actual projects with budgets that result in hardware is what really counts. Wish it weren't true but that's the case.