Why? LSTM as such isn't patented, so the concept is free to use by anyone without any restrictions or royalties, no matter who invented it.
Also, the concept of LSTM wouldn't be patentable directly even in the current liberal software patent interpretation, you might patent particular applications of LSTM (e.g. this patent) but not any and all arbitrary applications of LSTM.
Why is having R a limitation? R is a fantastic data language which arguably beats all others in terms of number of libraries and data manipulation tools.
If GP comes from a more software-dev background, I can understand a general dislike for R. There's lots of things where R can't be beat right now, but for simple data analysis and visualization, there's some damn good python packages like pandas and d3py that GP may find easier to use than dataframes/tables and rCharts in R.
R has no native bayesian library like Pymc 3 (Must use stan which is c++). Also Python is better for ad hoc and agent based modeling and for out of core data with blaze and dask.
Unless you can help here, I see alot of pre coded models and older samplers, but nothing with a flexible JIT for user extensible variab;es and autodiff for newer HMC and NUTS type samplers. Exception being STAN, but that is its own C++ modeling language, can't talk to R functions , is more verbose than PYMC 3 and doesn't do discrete variables (unlike pymc3).